Determination of Positioning Reference Signal Resources in Out-of-Coverage Sidelink-Aided Cooperative Positioning

Abstract

In one aspect, a technique for wireless communication is disclosed in which an assisting user equipment (UE) receives a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, where both the assisting UE and the target UE are out of network coverage. The assisting UE determines, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure, and transmits the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

Description

Priority claims

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 991,895, entitled "DETERMINATION OF POSITIONING REFERENCE SIGNAL RESOURCES IN OUT-OF-COVERAGE SIDELINK-ASSISTED COOPERATIVE POSITIONING," filed March 19, 2020, and U.S. Provisional Patent Application No. 17 / 160,029, entitled "DETERMINATION OF POSITIONING REFERENCE SIGNAL RESOURCES IN OUT-OF-COVERAGE SIDELINK-ASSISTED COOPERATIVE POSITIONING," filed January 27, 2021, both of which provisional applications are assigned to the assignee of the present patent application and are expressly incorporated herein by reference in their entireties. [Technical Field]

[0002] Aspects of the present disclosure generally relate to wireless communications. [Background technology]

[0003] Wireless communication systems have evolved through various generations, including first-generation analog wireless telephone service (1G), second-generation (2G) digital wireless telephone service (including intermediate 2.5G and 2.75G networks), third-generation (3G) high-speed data, Internet-enabled wireless service, and fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). Currently, there are many different types of wireless communication systems in use, including cellular and personal communications services (PCS) systems. Examples of known cellular systems include the Cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile Communications (GSM), etc.

[0004]

[0004] The fifth-generation (5G) wireless standard, known as New Radio (NR), requires, among other improvements, higher data rates, a greater number of connections, and better coverage. The 5G standard from the Next Generation Mobile Network Alliance is designed to provide data rates of tens of megabits per second to each of tens of thousands of users and 1 gigabit per second to dozens of workers on an office floor. To support large sensor deployments, hundreds of thousands of simultaneous connections should be supported. Therefore, the spectral efficiency of 5G mobile communications should be significantly enhanced compared to the current 4G standard. Furthermore, signaling efficiency should be enhanced and latency should be significantly reduced compared to current standards.

[0005]

[0005] In particular, leveraging the increased data rates and reduced latency of 5G, vehicle-to-everything (V2X) communication technologies are being implemented to support autonomous driving applications, such as wireless communications between vehicles, between vehicles and roadside infrastructure, between vehicles and pedestrians, etc. Summary of the Invention

[0006] The following presents a simplified summary related to one or more aspects disclosed herein. As such, the following summary is not intended to be an extensive overview related to all contemplated aspects, nor is it intended to identify key or critical elements related to all contemplated aspects or to delineate the scope related to particular aspects. As such, the following summary has the sole purpose of presenting some concepts related to one or more aspects related to the mechanisms disclosed herein in a simplified form as a prelude to the detailed description presented below.

[0007]

[0007] In one aspect, a method for wireless communication implemented in an assisting user equipment (UE) includes receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, where both the assisting UE and the target UE are out of network coverage; determining, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0008]

[0008] In one aspect, a method for wireless communication implemented in a target user equipment (UE) includes: transmitting a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determining, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and transmitting the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0009]

[0009] In one aspect, an assisting user equipment (UE) includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, wherein the at least one processor is configured to: receive a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, where both the assisting UE and the target UE are out of network coverage; determine, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and cause the at least one transceiver to transmit the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0010]

[0010] In one aspect, a target user equipment (UE) includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, wherein the at least one processor is configured to: cause the at least one transceiver to transmit a request to perform a positioning procedure to the at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determine, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and cause the at least one transceiver to transmit the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0011]

[0011] In one aspect, a assisting user equipment (UE) includes means for receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, where both the assisting UE and the target UE are out of network coverage; means for determining, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and means for transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0012]

[0012] In one aspect, a target user equipment (UE) includes means for transmitting a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; means for determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and means for transmitting the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0013] In one aspect, a non-transitory computer-readable medium stores a set of instructions including one or more instructions that, when executed by one or more processors of an assisting user equipment (UE), cause the assisting UE to: receive a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, where both the assisting UE and the target UE are out of network coverage; determine, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and transmit the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0014] A non-transitory computer-readable medium stores a set of instructions including one or more instructions that, when executed by one or more processors of a target user equipment (UE), cause the target UE to: send a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, where both the target UE and the at least one assisting UE are out of network coverage; determine, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and transmit the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0015] Other objects and advantages associated with the embodiments disclosed herein will become apparent to those skilled in the art based on the accompanying drawings and detailed description.

[0016]

[0016] The accompanying drawings are presented to aid in the explanation of various aspects of the present disclosure and are provided merely to illustrate, not to limit, the aspects. [Brief explanation of the drawings]

[0017] [Figure 1]

[0017] FIG. 1 illustrates an exemplary wireless communication system according to aspects of the present disclosure. [Figure 2A]

[0018] FIG. 1 illustrates an example wireless network structure, according to aspects of the present disclosure. [Figure 2B] FIG. 1 illustrates an example wireless network structure, according to aspects of the present disclosure. [Figure 3]

[0019] FIG. 1 illustrates an example of a wireless communication system supporting unicast sidelink establishment, according to aspects of the present disclosure. [Figure 4]

[0020] FIG. 1 is a block diagram illustrating various components of an exemplary user equipment (UE), according to aspects of the present disclosure. [Figure 5]

[0021] 1 illustrates an example frame structure for use in a wireless telecommunications system, according to an aspect of the present disclosure. [Figure 6]

[0022] FIG. 1 illustrates an example wireless communication system in which a vehicular user equipment (V-UE) is exchanging ranging signals with a roadside unit (RSU) and another V-UE, according to aspects of the present disclosure. [Figure 7]

[0023] FIG. 1 is a timeline diagram illustrating a three-phase communication protocol, according to an aspect of the present disclosure. [Figure 8]

[0024] FIG. 1 illustrates two resource allocation modes for transmission on the sidelink, according to an aspect of the present disclosure. [Figure 9]

[0025] FIG. 1 illustrates how a shared channel (SCH) is established on a sidelink between two or more UEs, according to an aspect of the present disclosure. [Figure 10]

[0026] 10A-10C illustrate example timing of round trip time (RTT) signals exchanged between a target UE and two assisting UEs, according to aspects of the present disclosure. [Figure 11]10A-10C illustrate example timing of round trip time (RTT) signals exchanged between a target UE and two assisting UEs, according to aspects of the present disclosure. [Figure 12]

[0027] FIG. 1 illustrates a relative time and frequency relationship between example physical sidelink shared channel (PSSCH) resources and example positioning reference signal (PRS) resources, in accordance with aspects of the present disclosure. [Figure 13]

[0028] FIG. 1 illustrates an example method for wireless communication, according to an aspect of the present disclosure. [Figure 14] FIG. 1 illustrates an example method for wireless communication, according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018]

[0029] Aspects of the present disclosure are provided in the following description and related drawings, directed to various examples provided for purposes of illustration. Alternative aspects may be devised without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the present disclosure.

[0019]

[0030] The words "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the described feature, advantage or mode of operation.

[0020]

[0031] Those skilled in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, in part on the desired design, in part on the corresponding technology, etc.

[0021]

[0032] Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be appreciated that various actions described herein may be performed by particular circuitry (e.g., an application-specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or a combination of both. Furthermore, a sequence of actions described herein may be considered to be embodied as a whole in any form of non-transitory computer-readable storage medium storing a corresponding set of computer instructions that, when executed, cause or instruct associated processors of a device to perform the functions described herein. Accordingly, various aspects of the present disclosure may be embodied in a number of different forms, all of which are contemplated to be within the scope of the claimed subject matter. Furthermore, for each aspect described herein, the corresponding form of any such aspect may be described herein as, for example, “logic configured to” perform the described actions.

[0022]

[0033] As used herein, the terms “user equipment” (UE), “vehicle UE” (V-UE), “pedestrian UE” (P-UE), and “base station” are not intended to be specific to, or as the case may be, limited to, any particular radio access technology (RAT) unless otherwise specified. Generally, a UE may be any wireless communication device used by a user to communicate over a wireless communication network (e.g., a vehicle on-board computer, a vehicle navigation device, a mobile phone, a router, a tablet computer, a laptop computer, a tracking device, a wearable (e.g., a smart watch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), a vehicle (e.g., an automobile, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.). A UE may be mobile or (e.g., at some times) stationary and may communicate with a radio access network (RAN). As used herein, the term “UE” may be referred to interchangeably as a “mobile device,” “access terminal” or “AT,” “client device,” “wireless device,” “subscriber device,” “subscriber terminal,” “subscriber station,” “user terminal” or UT,” “mobile terminal,” “mobile station,” or variations thereof.

[0023]

[0034] A V-UE is a type of UE and may be any in-vehicle wireless communication device, such as a navigation system, a warning system, a head-up display (HUD), an on-board computer, etc. Alternatively, a V-UE may be a portable wireless communication device (e.g., a cell phone, a tablet computer, etc.) carried by a vehicle driver or a passenger in the vehicle. The term "V-UE" may refer to an in-vehicle wireless communication device or the vehicle itself, depending on the context. A P-UE is a type of UE and may be a portable wireless communication device carried by a pedestrian (i.e., a user not driving or riding in a vehicle). Generally, a UE can communicate with a core network via a RAN, through which the UE can be connected to external networks such as the Internet and other UEs. Of course, other mechanisms for connecting to a core network and / or the Internet are also possible for a UE, such as via a wired access network, a wireless local area network (WLAN) network (e.g., based on Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc.), etc.

[0024]

[0035] A base station may operate according to one of several RATs communicating with UEs depending on the network in which it is deployed and may alternatively be referred to as an access point (AP), network node, Node B, evolved Node B (eNB), next-generation eNB (ng-eNB), new radio (NR) Node B (also referred to as gNB or gNode B), etc. Base stations may be used primarily to support wireless access by UEs, including supporting data, voice, and / or signaling connections for supported UEs. In some systems, a base station may provide purely edge node signaling functionality, while in other systems, it may provide additional control and / or network management functions. A communication link through which a UE can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which a base station can send signals to a UE is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term Traffic Channel (TCH) can refer to either an UL / reverse traffic channel or a DL / forward traffic channel.

[0025]

[0036] The term "base station" may refer to a single physical transmit receiving point (TRP) or multiple physical TRPs, which may or may not be collocated. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to the base station's cell (or several cell sectors). When the term "base station" refers to multiple collocated physical TRPs, the physical TRP may be an array of antennas of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or when the base station employs beamforming). When the term "base station" refers to multiple non-collocated physical TRPs, the physical TRP may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-collocated physical TRPs may be a serving base station that receives measurement reports from a UE and a neighbor base station whose reference radio frequency (RF) signal the UE is measuring. A TRP is a point from which a base station transmits and receives wireless signals, and therefore, as used herein, references to transmission from or reception at a base station should be understood as referring to the particular TRP of the base station.

[0026]

[0037] In some implementations that support UE positioning, a base station may not support wireless access by the UE (e.g., may not support data, voice, and / or signaling connections for the UE), but instead may transmit reference RF signals to the UE to be measured by the UE and / or may receive and measure signals transmitted by the UE. Such a base station may be referred to as a positioning beacon (e.g., when transmitting RF signals to the UE) and / or a location measurement unit (e.g., when receiving and measuring RF signals from the UE).

[0027]

[0038] An "RF signal" comprises electromagnetic waves of a given frequency that transport information through space between a transmitter and a receiver. As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, the receiver may receive multiple "RF signals" corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through a multipath channel. The same transmitted RF signal on different paths between a transmitter and a receiver is sometimes referred to as a "multipath" RF signal. As used herein, an RF signal may be referred to as a "wireless signal" or simply as a "signal" when it is clear from the context that the term "signal" refers to a wireless signal or an RF signal.

[0028]

[0039] 1 illustrates an exemplary wireless communication system 100. The wireless communication system 100 (sometimes referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled “BS”) and various UEs 104. The base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macrocell base stations 102 may include eNBs and / or ng-eNBs where the wireless communication system 100 corresponds to an LTE network, or gNBs where the wireless communication system 100 corresponds to an NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

[0029]

[0040] The base stations 102 collectively form the RAN and may interface with a core network 174 (e.g., Evolved Packet Core (EPC) or 5G Core (5GC)) through backhaul links 122 and through the core network 174 to one or more location servers 172 (which may be part of the core network 174 or external to the core network 174). In addition to other functions, the base stations 102 may perform functions related to one or more of forwarding user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for Non-Access Stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, Multimedia Broadcast Multicast Services (MBMS), subscriber and equipment tracing, RAN Information Management (RIM), paging, positioning, and delivery of alert messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through EPC / 5GC) via backhaul links 134, which may be wired or wireless.

[0030]

[0041] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In one aspect, one or more cells may be supported by the base stations 102 in each geographic coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, etc.) and may be associated with an identifier (e.g., a physical cell identifier (PCI), an extended cell identifier (ECI), a virtual cell identifier (VCI), a cell global identifier (CGI), etc.) to distinguish cells operating over the same or different carrier frequencies. In some cases, different cells may be configured according to different protocol types (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access to different types of UEs. Because a cell is supported by a particular base station, the term “cell” may refer to either or both the logical communication entity and the base station that supports it, depending on the context. In some cases, the term "cell" may also refer to the geographic coverage area (e.g., sector) of a base station, so long as the carrier frequency can be detected and used for communication within some portion of the geographic coverage area 110.

[0031]

[0042] The geographic coverage areas 110 of neighboring macrocell base stations 102 may partially overlap (e.g., in handover regions), but some of the geographic coverage areas 110 may be significantly overlapped by larger geographic coverage areas 110. For example, a small cell base station 102' (labeled "SC" for "small cell") may have a geographic coverage area 110' that significantly overlaps with the geographic coverage area 110 of one or more macrocell base stations 102. A network including both small cell and macrocell base stations may be known as a heterogeneous network. A heterogeneous network may also include Home eNBs (HeNBs) that may serve restricted groups known as Closed Subscriber Groups (CSGs).

[0032]

[0043] The communication link 120 between the base station 102 and the UE 104 may include uplink transmissions (also called reverse link) from the UE 104 to the base station 102, and / or downlink (DL) transmissions (also called forward link) from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna techniques, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be over one or more carrier frequencies. The allocation of carriers may be asymmetric with respect to the downlink and uplink (e.g., more or fewer carriers may be allocated for the downlink than for the uplink).

[0033]

[0044] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (AP) 150 communicating with a WLAN station (STA) 152 via a communication link 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in the unlicensed frequency spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) procedure or a listen-before-talk (LBT) procedure before communicating to determine whether a channel is available.

[0034]

[0045] The small cell base station 102' may operate in licensed and / or unlicensed frequency spectrums. When operating in the unlicensed frequency spectrum, the small cell base station 102' may employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum used by the WLAN AP 150. A small cell base station 102' employing LTE / 5G in the unlicensed frequency spectrum may boost coverage to and / or increase the capacity of the access network. NR in the unlicensed spectrum may be referred to as NR-U. LTE in the unlicensed spectrum may be referred to as LTE-U, Licensed Assisted Access (LAA), or MultiFire.

[0035]

[0046] The wireless communication system 100 may further include an mmW base station 180 that may operate in mmW and / or near-mmW frequencies and that is in communication with the UE 182. Extremely high frequency (EHF) is the RF portion of the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band are sometimes called millimeter waves. Near-mmW may extend down to frequencies of 3 GHz, with wavelengths of 100 millimeters. The very high frequency (SHF) band, also called centimeter wave, extends between 3 GHz and 30 GHz. Communications using the mmW / near-mmW radio frequency bands have high path loss and relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and / or receive) over the mmW communication link 184 to compensate for the extremely high path loss and short range. Furthermore, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the above description is by way of example only and should not be construed as limiting various aspects disclosed herein.

[0036]

[0047] Transmit beamforming is a technique for focusing an RF signal in a particular direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). With transmit beamforming, the network node determines where a given target device (e.g., UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that particular direction, thereby providing a faster (in terms of data rate) and stronger RF signal to the receiving device(s). To change the directionality of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node may use an array of antennas (called a “phased array” or “antenna array”) that creates beams of RF waves that can be “steered” to point in different directions without actually moving the antennas. In particular, RF current from the transmitter is supplied to individual antennas with the proper phase relationship so that the waves from the separate antennas add together to increase radiation in desired directions while canceling and suppressing radiation in undesired directions.

[0037]

[0048] A transmit beam may be quasi-colocated, meaning that the transmit beam appears to a receiver (e.g., a UE) to have the same parameters regardless of whether the network node's transmit antennas themselves are physically colocated. In NR, there are four types of quasi-colocation (QCL) relationships. In particular, a given type of QCL relationship means that some parameters related to a second reference RF signal on a second beam can be derived from information about the source reference RF signal on the source beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, mean delay, and delay spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and mean delay of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate spatial reception parameters of a second reference RF signal transmitted on the same channel.

[0038]

[0049] In receive beamforming, a receiver uses receive beams to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of an antenna array in a particular direction to amplify (e.g., increase its gain level) an RF signal received from that direction. Thus, when a receiver is said to beamform in a direction, it means that the beam gain in that direction is higher relative to the beam gains along other directions, or that the beam gain in that direction is highest compared to the beam gains in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of the RF signal received from that direction.

[0039]

[0050] The transmit beam and the receive beam may be spatially related. The spatial relationship means that parameters for a second beam (e.g., a transmit or receive beam) of a second reference signal may be derived from information about a first beam (e.g., a receive or transmit beam) of a first reference signal. For example, a UE may use a particular receive beam to receive a reference downlink reference signal (e.g., a synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam for sending an uplink reference signal (e.g., a sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0040]

[0051] Note that a "downlink" beam can be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station forms a downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. However, if the UE forms a downlink beam, it is a receive beam to receive the downlink reference signal. Similarly, an "uplink" beam can be either a transmit beam or a receive beam, depending on the entity forming it. For example, if the base station forms an uplink beam, it is an uplink receive beam, and if the UE forms an uplink beam, it is an uplink transmit beam.

[0041]

[0052] In 5G, the frequency spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (450 to 6000 MHz), FR2 (24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). The mmW frequency band generally includes the FR2, FR3, and FR4 frequency ranges. Thus, the terms “mmW” and “FR2” or “FR3” or “FR4” may generally be used interchangeably.

[0042]

[0053] In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and the cell on which the UE 104 / 182 either performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels and may be a carrier in licensed frequencies (although this is not always the case). The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once an RRC connection is established between the UE 104 and the anchor carrier and may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in unlicensed frequencies. The secondary carrier may contain only the necessary signaling information and signals; for example, nothing UE-specific may be present in the secondary carrier, since both the primary uplink carrier and the primary downlink carrier are typically UE-specific. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carrier. The network may change the primary carrier of any UE 104 / 182 at any time. This is done, for example, to balance the load on different carriers. Since a "serving cell" (whether a PCell or an SCell) corresponds to the carrier frequency / component carrier over which some base station is communicating, terms such as "cell," "serving cell," "component carrier," and "carrier frequency" may be used interchangeably.

[0043]

[0054] For example, still referring to FIG. 1, one of the frequencies utilized by the macrocell base station 102 may be an anchor carrier (or “PCell”), and other frequencies utilized by the macrocell base station 102 and / or the mmW base station 180 may be secondary carriers (“SCells”). Simultaneous transmission and / or reception of multiple carriers allows the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically lead to a doubling of the data rate (i.e., 40 MHz) compared to that achieved by a single 20 MHz carrier.

[0044]

[0055] In the example of FIG. 1, one or more Earth-orbiting Satellite Positioning System (SPS) space vehicles (SVs) 112 (e.g., satellites) may be used as independent sources of location information for any of the illustrated UEs (shown in FIG. 1 as a single UE 104 for simplicity). The UE 104 may include one or more dedicated SPS receivers specially designed to receive SPS signals 124 to derive geolocation information from the SVs 112. An SPS typically includes a system of transmitters positioned to enable a receiver (e.g., UE 104) to determine its location on or above the Earth based at least in part on signals (e.g., SPS signals 124) received from a transmitter (e.g., SV 112). Such transmitters typically transmit signals marked with a repetitive pseudorandom noise (PN) code of a set number of chips. While typically located in the SVs 112, transmitters may sometimes be located on ground-based control stations, base stations 102, and / or other UEs 104.

[0045]

[0056] Use of SPS signals 124 may be augmented by various satellite-based augmentation systems (SBAS), which may be associated with or otherwise enabled for use with one or more global and / or regional navigation satellite systems. For example, SBAS may include augmentation system(s) that provide integrity information, differential corrections, etc., such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), the Global Positioning System (GPS)-aided Geo Augmented Navigation or GPS and Geo Augmented Navigation system (GAGAN), etc. Thus, as used herein, SPS may include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and SPS signals 124 may include SPS signals, SPS-like signals, and / or other signals related to such one or more SPSs.

[0046]

[0057] In particular, leveraging NR's increased data rates and reduced latency, vehicle-to-everything (V2X) communication technology is being implemented to support intelligent transport systems (ITS) applications, such as wireless communications between vehicles (vehicle-to-vehicle (V2V)), between vehicles and roadside infrastructure (vehicle-to-infrastructure (V2I)), and between vehicles and pedestrians (vehicle-to-pedestrian (V2P)). The goal is for vehicles to sense their surrounding environment and communicate that information to other vehicles, infrastructure, and personal mobile devices. Such vehicular communications enable safety, mobility, and environmental improvements that current technology cannot provide. When fully implemented, the technology is expected to reduce unimpaired vehicle crashes by 80%.

[0047]

[0058] Still referring to FIG. 1 , the wireless communication system 100 may include multiple V-UEs 160, which may communicate with the base station 102 via communication link 120 (e.g., using the Uu interface). The V-UEs 160 may also communicate directly with each other via wireless sidelink 162, with a roadside access point 164 (also referred to as a “roadside unit”) via wireless sidelink 166, or with the UE 104 via wireless sidelink 168. Wireless sidelink (or simply “sidelink”) is an adaptation of the core cellular (e.g., LTE, NR) standard that enables direct communication between two or more UEs without the communication having to go through a base station. Sidelink communication may be unicast or multicast and may be used for device-to-device (D2D) media sharing, V2V communication, V2X communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, etc. One or more of a group of V-UEs 160 utilizing sidelink communications may be within the geographic coverage area 110 of the base station 102. Other V-UEs 160 in such a group may be outside the geographic coverage area 110 of the base station 102 or may otherwise be unable to receive transmissions from the base station 102. In some cases, a group of V-UEs 160 communicating via sidelink communications may utilize a one-to-many (1:M) system in which each V-UE 160 transmits to every other V-UE 160 in the group. In some cases, the base station 102 facilitates scheduling of resources for sidelink communications. In other cases, sidelink communications occur between V-UEs 160 without the involvement of the base station 102.

[0048]

[0059] In one aspect, the sidelinks 162, 166, 168 may operate over a wireless communication medium of interest that may be shared with other vehicular and / or infrastructure access points, as well as other wireless communications between other RATs. The “medium” may consist of one or more time, frequency, and / or spatial communication resources (e.g., encompassing one or more channels across one or more carriers) associated with wireless communications between one or more transmitter / receiver pairs.

[0049]

[0060] In one aspect, the sidelinks 162, 166, 168 may be cV2X links. The first generation of cV2X has been standardized in LTE, and the next generation is expected to be defined in NR. cV2X is a cellular technology that also enables device-to-device communications. In the United States and Europe, cV2X is expected to operate in licensed ITS bands in the sub-6 GHz range. In other countries, other bands may be allocated. Thus, as a specific example, the medium of interest utilized by the sidelinks 162, 166, 168 may correspond to at least a portion of the sub-6 GHz licensed ITS frequency band. However, the present disclosure is not limited to this frequency band or cellular technology.

[0050]

[0061] In one aspect, the sidelinks 162, 166, 168 may be dedicated short-range communication (DSRC) links. DSRC is a one-way or two-way short- to medium-range wireless communication protocol that uses the wireless access for vehicular environments (WAVE) protocol, also known as IEEE 802.11p, for V2V, V2I, and V2P communications. IEEE 802.11p is an approved amendment to the IEEE 802.11 standard and operates in the licensed ITS band at 5.9 GHz (5.85-5.925 GHz) in the United States. In Europe, IEEE 802.11p operates in the ITS G5A band (5.875-5.905 MHz). Other bands may be allocated in other countries. The V2V communications briefly described above occur over a safety channel, which in the United States is typically a 10 MHz channel dedicated to safety purposes. The remainder of the DSRC band (total bandwidth of 75 MHz) is intended for other services of interest to drivers, such as road regulations, toll collection, and automated parking. Thus, as a specific example, the medium of interest utilized by sidelinks 162, 166, 168 may correspond to at least a portion of the 5.9 GHz licensed ITS frequency band.

[0051]

[0062] Alternatively, the medium of interest may correspond to at least a portion of an unlicensed frequency band shared among various RATs. While different licensed frequency bands have been reserved for some communication systems (e.g., by government agencies such as the Federal Communications Commission (FCC) in the United States), these systems, particularly those employing small cell access points, have recently extended operation to unlicensed frequency bands, such as the Unlicensed National Information Infrastructure (U-NII) bands used by Wireless Local Area Network (WLAN) technologies, most notably the IEEE 802.11x WLAN technology commonly referred to as "Wi-Fi." Exemplary systems of this type include different variants of CDMA systems, TDMA systems, FDMA systems, Orthogonal FDMA (OFDMA) systems, Single-Carrier FDMA (SC-FDMA) systems, etc.

[0052]

[0063] Communication between V-UEs 160 is referred to as V2V communication, communication between V-UEs 160 and one or more roadside access points 164 is referred to as V2I communication, and communication between V-UEs 160 and one or more UEs 104 (where UEs 104 are P-UEs) is referred to as V2P communication. V2V communication between V-UEs 160 may include, for example, information regarding the position, speed, acceleration, orientation, and other vehicle data of V-UEs 160. V2I information received at V-UEs 160 from one or more roadside access points 164 may include, for example, road rules, parking automation information, etc. V2P communication between V-UEs 160 and UEs 104 may include, for example, information regarding the position, speed, acceleration, and orientation of V-UEs 160, as well as the position, speed (e.g., if UE 104 is carried by a user on a bicycle), and orientation of UEs 104.

[0053]

[0064] Note that while FIG. 1 illustrates only two of the UEs as V-UEs (V-UE 160), any of the illustrated UEs (e.g., UEs 104, 152, 182, 190) could be V-UEs. Furthermore, while only V-UE 160 and a single UE 104 are shown as connected via sidelink, any of the UEs illustrated in FIG. 1 could be capable of sidelink communication, whether a V-UE or a P-UE, etc. Furthermore, while only UE 182 is described as being capable of beamforming, any of the illustrated UEs, including V-UE 160, could be capable of beamforming. If V-UE 160 were capable of beamforming, they could beamform toward each other (i.e., toward other V-UEs 160), toward roadside access point 164, toward other UEs (e.g., UEs 104, 152, 182, 190), etc. Thus, in some cases, V-UE 160 may utilize beamforming over sidelinks 162, 166, and 168.

[0054]

[0065] The wireless communication system 100 may further include one or more UEs, such as a UE 190, that indirectly connect to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In the example of FIG. 1, the UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which the UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (through which the UE 190 may indirectly obtain WLAN-based Internet connectivity). In one example, the D2D P2P links 192 and 194 may be supported using any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct® (WiFi®-D), Bluetooth®, etc. As another example, the D2D P2P links 192 and 194 may be sidelinks, such as those described above with respect to the sidelinks 162, 166, and 168.

[0055]

[0066] 2A illustrates an exemplary wireless network structure 200. For example, a 5GC 210 (also referred to as a Next Generation Core (NGC)) may be functionally considered to include a control plane function (C-plane) 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane function (U-plane) 212 (e.g., UE gateway function, data network access, IP routing, etc.), which operate cooperatively to form a core network. A user plane interface (NG-U) 213 and a control plane interface (NG-C) 215 connect a gNB 222 to the 5GC 210, specifically to the user plane function 212 and the control plane function 214, respectively. In an additional configuration, an ng-eNB 224 may also be connected to the 5GC 210 via the NG-C 215 to the control plane function 214 and the NG-U 213 to the user plane function 212. Additionally, the ng-eNB 224 may communicate directly with the gNB 222 via a backhaul connection 223. In some configurations, the next generation RAN (NG-RAN) 220 may have only one or more gNBs 222, while other configurations include one or more of both an ng-eNB 224 and a gNB 222. Either the gNB 222 or the ng-eNB 224 (or both) may communicate with a UE 204 (e.g., any of the UEs described herein). In one aspect, two or more UEs 204 may communicate with each other via a wireless sidelink 242, which may correspond to the wireless sidelink 162 in FIG. 1.

[0056]

[0067] Another optional aspect may include a location server 230, which may be in communication with the 5GC 210 to provide location assistance to the UE 204. The location servers 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternatively, may each correspond to a single server. The location servers 230 may be configured to support one or more location services for UEs 204 that can connect to the location server 230 via the core network, the 5GC 210, and / or the Internet (not shown). Furthermore, the location server 230 may be incorporated into a component of the core network or alternatively may be external to the core network.

[0057]

[0068] 2B shows another exemplary wireless network structure 250. For example, a 5GC 260 may be considered functionally as a control plane function provided by an access and mobility management function (AMF) 264 and a user plane function provided by a user plane function (UPF) 262, which operate cooperatively to form a core network (i.e., the 5GC 260). A user plane interface 263 and a control plane interface 265 connect the ng-eNB 224 to the 5GC 260, specifically to the UPF 262 and the AMF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the 5GC 260 via the control plane interface 265 to the AMF 264 and the user plane interface 263 to the UPF 262. Additionally, the ng-eNB 224 may communicate directly with the gNB 222 via the backhaul connection 223, with or without gNB direct connectivity to the 5GC 260. In some configurations, the NG-RAN 220 may have only one or more gNBs 222, while other configurations include one or more of both the ng-eNB 224 and the gNB 222. The base stations of the NG-RAN 220 communicate with the AMF 264 via an N2 interface and with the UPF 262 via an N3 interface. Either (or both) of the gNBs 222 or the ng-eNB 224 may communicate with a UE 204 (e.g., any of the UEs described herein). In one aspect, two or more UEs 204 may communicate with each other via a sidelink 242, which may correspond to the sidelink 162 in FIG. 1.

[0058]

[0069] The AMF 264 functions include registration management, connection management, reachability management, mobility management, lawful intercept, transport for session management (SM) messages between the UE 204 and a session management function (SMF) 266, a transparent proxy service for routing SM messages, access authentication and authorization, transport for short message service (SMS) messages between the UE 204 and a short message service function (SMSF) (not shown), and a security anchor function (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204 to receive intermediate keys established as a result of the UE 204 authentication process. In the case of UMTS (Universal Mobile Telecommunications System) subscriber identity module (USIM)-based authentication, the AMF 264 retrieves security material from the AUSF. The AMF 264 functions also include security context management (SCM). The SCM receives keys from the SEAF that it uses to derive access network-specific keys. The AMF 264 functions also include location service management for barred services, transport for location service messages between the UE 204 and a location management function (LMF) 270 acting as the location server 230, transport for location service messages between the NG-RAN 220 and the LMF 270, Evolved Packet System (EPS) bearer identifier allocation for interworking with EPS, and UE 204 mobility event notification. Additionally, the AMF 264 also supports functions for non-3GPP (Third Generation Partnership Project) access networks.

[0059]

[0070] The functions of the UPF 262 include serving as an anchor point for intra / inter-RAT mobility (when applicable), serving as an outer protocol data unit (PDU) session point for interconnection to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink / downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic validation (service data flow (SDF) to QoS flow mapping), transport-level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding one or more "termination markers" to the source RAN node. The UPF 262 may also support the transfer of location service messages over the user plane between the UE 204 and a location server such as the Secure User Plane Location (SUPL) Location Platform (SLP) 272.

[0060]

[0071] The functions of the SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering in the UPF 262 to route traffic to the appropriate destination, control of policy enforcement and parts of QoS, and downlink data notification. The interface through which the SMF 266 communicates with the AMF 264 is called the N11 interface.

[0061]

[0072] Another optional aspect may include an LMF 270, which may be in communication with the 5GC 260 to provide location assistance to the UE 204. The LMF 270 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternatively, may each correspond to a single server. The LMF 270 may be configured to support one or more location services for UEs 204 that can connect to the LMF 270 via a core network, the 5GC 260, and / or via the Internet (not shown). The SLP 272 may support similar functions as the LMF 270, but the LMF 270 may communicate with the AMF 264, the NG-RAN 220, and the UE 204 via a control plane (e.g., using interfaces and protocols intended to carry signaling messages rather than voice or data), and the SLP 272 may communicate with the UE 204 and external clients (not shown in FIG. 2B) via a user plane (e.g., using protocols intended to carry voice and / or data, such as Transmission Control Protocol (TCP) and / or IP).

[0062]

[0073] 3 illustrates an example of a wireless communication system 300 supporting wireless unicast sidelink establishment according to aspects of the present disclosure. In some examples, the wireless communication system 300 may implement aspects of the wireless communication systems 100, 200, and 250. The wireless communication system 300 may include a first UE 302 and a second UE 304, which may be examples of any of the UEs described herein. As specific examples, the UEs 302 and 304 may correspond to the V-UE 160 in FIG. 1, the UE 190 and UE 104 in FIG. 1 connected via the D2D P2P link 192, or the UE 204 in FIG. 2A and 2B.

[0063]

[0074] In the example of FIG. 3, the UE 302 may attempt to establish a unicast connection over a sidelink with the UE 304, which may be a V2X sidelink between the UE 302 and the UE 304. As a specific example, the established sidelink connection may correspond to sidelinks 162 and / or 168 in FIG. 1 or sidelink 242 in FIGS. 2A and 2B. The sidelink connection may be established in an omnidirectional frequency range (e.g., FR1) and / or an mmW frequency range (e.g., FR2). In some cases, the UE 302 may be referred to as an initiating UE that initiates the sidelink connection procedure, and the UE 304 may be referred to as a target UE that is the subject of the sidelink connection procedure by the initiating UE.

[0064]

[0075] To establish a unicast connection, access stratum (AS) (a functional layer in the UMTS and LTE protocol stack between the RAN and the UE, responsible for transporting data over the wireless link and managing radio resources and part of Layer 2) parameters may be configured and negotiated between the UE 302 and the UE 304. For example, transmit and receive capability matching may be negotiated between the UE 302 and the UE 304. Each UE may have different capabilities (e.g., transmit and receive, 64-quadrature amplitude modulation (QAM), transmit diversity, carrier aggregation (CA), supported communication frequency band(s), etc.). In some cases, different services may be supported at higher layers of the corresponding protocol stacks for the UE 302 and the UE 304. Furthermore, a security association may be established between the UE 302 and the UE 304 for the unicast connection. Unicast traffic may benefit from security protection (e.g., integrity protection) at the link level. Security requirements may differ for different wireless communication systems. For example, a V2X system and a Uu system may have different security requirements (e.g., Uu security does not include confidentiality protection). Additionally, IP configurations (e.g., IP version, addresses, etc.) may be negotiated for unicast connections between UE 302 and UE 304.

[0065]

[0076] In some cases, the UE 304 may create a service announcement (e.g., a service capability message) to transmit over a cellular network (e.g., cV2X) to assist in sidelink connection establishment. Traditionally, the UE 302 may identify and locate candidates for sidelink communication based on a broadcasted basic service message (BSM) decrypted by a nearby UE (e.g., the UE 304). The BSM may include location information, security and identification information, and vehicle information (e.g., speed, operation, size, etc.) for the corresponding UE. However, for different wireless communication systems (e.g., D2D or V2X communications), a discovery channel may not be configured to enable the UE 302 to detect the BSM(s). Therefore, the service announcement (e.g., a discovery signal) transmitted by the UE 304 and other nearby UEs is a higher layer signal and may be broadcast (e.g., in an NR sidelink broadcast). In some cases, the UE 304 may include one or more parameters about itself, including its own connection parameters and / or capabilities, in the service announcement. The UE 302 may then monitor and receive the broadcasted service announcements to identify potential UEs for the corresponding sidelink connection. In some cases, the UE 302 may identify potential UEs based on the capabilities each UE indicates in its respective service announcement.

[0066]

[0077] The service announcement may include information to assist the UE 302 (e.g., or any initiating UE) in identifying the UE (UE 304 in the example of FIG. 3) sending the service announcement. For example, the service announcement may include channel information if a direct communication request may be sent. In some cases, the channel information may be RAT-specific (e.g., specific to LTE or NR) and may include a resource pool within which the UE 302 sends the communication request. Furthermore, the service announcement may include a specific destination address (e.g., a Layer 2 destination address) for the UE if the destination address is different from the current address (e.g., the address of the streaming provider or the UE sending the service announcement). The service announcement may also include a network or transport layer for the UE 302 to send the communication request. For example, the network layer (also referred to as "Layer 3" or "L3") or the transport layer (also referred to as "Layer 4" or "L4") may indicate the port number of the application for the UE sending the service announcement. In some cases, IP addressing may not be required if the signaling (e.g., PC5 signaling) directly carries a protocol (e.g., Real-time Transport Protocol (RTP)) or provides a locally generated random protocol. Additionally, the service announcement may include some type of protocol for credential establishment and QoS-related parameters.

[0067]

[0078] After identifying a potential sidelink connection target (UE 304 in the example of FIG. 3 ), the initiating UE (UE 302 in the example of FIG. 3 ) may send a connection request 315 to the identified target UE 304. In some cases, the connection request 315 may be the first RRC message (e.g., an “RRCDirectConnectionSetupRequest” message) sent by the UE 302 to request a unicast connection with the UE 304. For example, the unicast connection may utilize the PC5 interface for the sidelink, and the connection request 315 may be an RRC Connection Setup Request message. Furthermore, the UE 302 may use the sidelink signaling radio bearer 305 to transport the connection request 315.

[0068]

[0079] After receiving the connection request 315, the UE 304 may determine whether to accept or reject the connection request 315. The UE 304 may base this decision on transmit / receive capabilities, an ability to accommodate a unicast connection over the sidelink, a particular service indicated for the unicast connection, content to be transmitted over the unicast connection, or a combination thereof. For example, if the UE 302 desires to use a first RAT to transmit or receive data but the UE 304 does not support the first RAT, the UE 304 may reject the connection request 315. Additionally or alternatively, the UE 304 may reject the connection request 315 based on an inability to accommodate a unicast connection over the sidelink due to limited radio resources, scheduling issues, etc. Accordingly, the UE 304 may send an indication of whether the request is accepted or rejected in a connection response 320. Similar to the UE 302 and the connection request 315, the UE 304 may use the sidelink signaling radio bearer 310 to transport the connection response 320. Additionally, the connection response 320 may be a second RRC message (eg, an “RRCDirectConnectionResponse” message) sent by the UE 304 in response to the connection request 315.

[0069]

[0080] In some cases, the sidelink signaling radio bearer 305 and the sidelink signaling radio bearer 310 may be the same sidelink signaling radio bearer or may be separate sidelink signaling radio bearers. Therefore, the radio link control (RLC) layer acknowledged mode (AM) may be used for the sidelink signaling radio bearers 305 and 310. UEs that support unicast connections may listen on logical channels associated with the sidelink signaling radio bearers. In some cases, the AS layer (i.e., Layer 2) may pass information directly through RRC signaling (e.g., control plane) instead of the V2X layer (e.g., data plane).

[0070]

[0081] If the connection response 320 indicates that the UE 304 accepted the connection request 315, the UE 302 may send a connection establishment 325 message on the sidelink signaling radio bearer 305 to indicate that the unicast connection setup is complete. In some cases, the connection establishment 325 may be a third RRC message (e.g., an "RRCDirectConnectionSetupComplete" message). Each of the connection request 315, connection response 320, and connection establishment 325 may use basic capabilities to enable each UE to be able to receive and decode the corresponding transmission (e.g., RRC message) when transported from one UE to the other.

[0071]

[0082] Additionally, an identifier may be used for each of the connection request 315, connection response 320, and connection establishment 325. For example, the identifier may indicate which UE 302 / 304 is sending which message and / or which UE 302 / 304 the message is intended for. On a physical (PHY) layer channel, RRC signaling and subsequent data transmissions may use the same identifier (e.g., Layer 2 ID). However, on a logical channel, identifiers may be separate for RRC signaling and for data transmissions. For example, on a logical channel, RRC signaling and data transmissions may be treated differently and have different acknowledgement (ACK) feedback messaging. In some cases, for RRC messaging, a physical layer ACK may be used to ensure that corresponding messages are properly transmitted and received.

[0072]

[0083] For a unicast connection, one or more information elements may be included in the connection request 315 and / or connection response 320 for the UE 302 and / or UE 304, respectively, to enable negotiation of corresponding AS layer parameters. For example, the UE 302 and / or UE 304 may include Packet Data Convergence Protocol (PDCP) parameters in a corresponding unicast connection setup message to set up a PDCP context for the unicast connection. In some cases, the PDCP context may indicate whether PDCP replication is utilized for the unicast connection. Furthermore, the UE 302 and / or UE 304 may include RLC parameters when establishing the unicast connection to set up an RLC context for the unicast connection. For example, the RLC context may indicate whether AM is used (e.g., a reordering timer (t-reordering) is used) or unacknowledged mode (UM) is used for the RLC layer of the unicast communication.

[0073]

[0084] Furthermore, the UE 302 and / or UE 304 may include MAC parameters to configure a medium access control (MAC) context for the unicast connection. In some cases, the MAC context may enable a resource selection algorithm, a hybrid automatic repeat request (HARQ) feedback scheme (e.g., ACK or negative ACK (NACK) feedback), parameters for the HARQ feedback scheme, carrier aggregation, or a combination thereof for the unicast connection. Furthermore, the UE 302 and / or UE 304 may include PHY layer parameters when establishing a unicast connection to configure a PHY layer context for the unicast connection. For example, the PHY layer context may indicate a transmission format and a radio resource configuration (e.g., bandwidth portion (BWP), numerology, etc.) for the unicast connection (unless a transmission profile is included for each UE 302 / 304). These information elements may be supported for different frequency range configurations (e.g., FR1 and FR2).

[0074]

[0085] In some cases, security contexts may also be set for unicast connections (e.g., after the connection establishment 325 message is sent). Before a security association (e.g., security context) is established between the UE 302 and the UE 304, the sidelink signaling radio bearers 305 and 310 may not be protected. After a security association is established, the sidelink signaling radio bearers 305 and 310 may be protected. Thus, security contexts may enable secure data transmission over unicast connections as well as the sidelink signaling radio bearers 305 and 310. Furthermore, IP layer parameters (e.g., link-local IPv4 or IPv6 addresses) may also be negotiated. In some cases, IP layer parameters may be negotiated by a higher layer control protocol operating after RRC signaling is established (e.g., the unicast connection is established). As mentioned above, the UE 304 may base its decision on whether to accept or reject the connection request 315 on the particular service indicated for the unicast connection and / or content to be transmitted over the unicast connection (e.g., higher layer information). The particular service and / or content may also be indicated by a higher layer control protocol operating after RRC signaling is established.

[0075]

[0086] After the unicast connection is established, the UE 302 and the UE 304 may communicate using a unicast connection over a sidelink 330, in which sidelink data 335 is transmitted between the two UEs 302 and 304. The sidelink 330 may correspond to the sidelinks 162 and / or 168 in FIG. 1 and / or the sidelink 242 in FIG. 2A and 2B. In some cases, the sidelink data 335 may include RRC messages transmitted between the two UEs 302 and 304. To maintain this unicast connection over the sidelink 330, the UE 302 and / or the UE 304 may transmit keep-alive messages (e.g., an "RRC Direct Link Alive" message, a fourth RRC message, etc.). In some cases, the keep-alive messages may be triggered periodically or on-demand (e.g., event-triggered). Thus, the triggering and transmission of keep-alive messages may be invoked by the UE 302 or by both the UE 302 and the UE 304. Additionally or alternatively, a MAC control element (CE) (e.g., defined over the sidelink 330) may be used to monitor the status of the unicast connection on the sidelink 330 and maintain that connection. When the unicast connection is no longer needed (e.g., the UE 302 travels far enough away from the UE 304), either the UE 302 and / or the UE 304 may initiate a release procedure to drop the unicast connection over the sidelink 330. Thus, subsequent RRC messages may not be transmitted between the UE 302 and the UE 304 over the unicast connection.

[0076]

[0087] FIG. 4 is a block diagram illustrating various components of an exemplary UE 400 according to aspects of the present disclosure. In one aspect, the UE 400 may correspond to any of the UEs described herein. As a specific example, the UE 400 may be a V-UE, such as the V-UE 160 in FIG. 1. For simplicity, the various features and functions illustrated in the block diagram of FIG. 4 are connected to each other using a common data bus, which is meant to represent that these various features and functions are operatively coupled to each other. Those skilled in the art will recognize that other connections, mechanisms, features, functions, etc. may be provided and adapted as needed to operatively couple and configure an actual UE. Furthermore, it should be recognized that one or more of the features or functions illustrated in the example of FIG. 4 may be further subdivided, or two or more of the features or functions illustrated in FIG. 4 may be combined.

[0077]

[0088] The UE 400 may include at least one transceiver 404 connected to one or more antennas 402, which at least one transceiver 404 provides means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) with other network nodes, such as a V-UE (e.g., V-UE 160), an infrastructure access point (e.g., roadside access point 164), a P-UE (e.g., UE 104), a base station (e.g., base station 102), etc., via at least one designated RAT (e.g., cV2X or IEEE 802.11p) over one or more communication links (e.g., communication link 120, sidelinks 162, 166, 168, mmW communication link 184). The transceiver 404 may be variously configured for transmitting and encoding signals (e.g., messages, instructions, information, etc.), and conversely, for receiving and decoding signals (e.g., messages, instructions, information, pilots, etc.) in accordance with the designated RAT.

[0078]

[0089] As used herein, a "transceiver" may, in some implementations, include at least one transmitter and at least one receiver in an integrated device (e.g., implemented as transmitter and receiver circuitry in a single communications device), may comprise separate transmitter and receiver devices in some implementations, or may be implemented in other manners in other implementations. In one aspect, a transmitter may include or be coupled to multiple antennas (e.g., antenna(s) 402) such as an antenna array that enables the UE 400 to perform transmit "beamforming" as described herein. Similarly, a receiver may include or be coupled to multiple antennas (e.g., antenna(s) 402) such as an antenna array that enables the UE 400 to perform receive beamforming as described herein. In one aspect, the transmitter(s) and receiver(s) may share the same multiple antennas (e.g., antenna(s) 402) such that the UE 400 can only receive or transmit at a given time rather than both receive and transmit simultaneously. In some cases, a transceiver may not provide both transmit and receive functionality. For example, to reduce cost when it is not necessary to provide full communication, some designs may employ reduced functionality receiver circuitry (e.g., a receiver chip or similar circuitry that simply provides low-level sniffing).

[0079]

[0090] The UE 400 may also include a satellite positioning service (SPS) receiver 406. The SPS receiver 406 may be connected to one or more antennas 402 and may provide a means for receiving and / or measuring satellite signals. The SPS receiver 406 may comprise any suitable hardware and / or software for receiving and processing SPS signals, such as Global Positioning System (GPS) signals. The SPS receiver 406 requests information and actions from other systems as appropriate and performs the calculations necessary to determine the position of the UE 400 using measurements obtained by any suitable SPS algorithms.

[0080]

[0091] One or more sensors 408 may be coupled to the processing system 410 and may provide a means for sensing or detecting information related to the state and / or environment of the UE 400, such as speed, heading (e.g., compass heading), headlight status, gas mileage, etc. By way of example, the one or more sensors 408 may include a speedometer, a tachometer, an accelerometer (e.g., a micro-electro-mechanical system (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), etc.

[0081]

[0092] The processing system 410 may include one or more microprocessors, microcontrollers, ASICs, processing cores, digital signal processors, etc. that provide processing functions as well as other computational and control functions. The processing system 410 may thus provide means for processing, such as means for determining, means for calculating, means for receiving, means for transmitting, means for instructing, etc. The processing system 410 may include any form of logic suitable to implement or cause components of the UE 400 to implement at least the techniques described herein.

[0082]

[0093] The processing system 410 may also be coupled to memory 414, which provides a means for storing (including a means for retrieving, a means for maintaining, etc.) data and software instructions for executing programmed functions within the UE 400. The memory 414 may be on-board the processing system 410 (e.g., in the same integrated circuit (IC) package) and / or the memory 414 may be external to the processing system 410 and operatively coupled via a data bus.

[0083]

[0094] The UE 400 may include a user interface 450 providing any suitable interface system, such as a microphone / speaker 452, a keypad 454, and a display 456, to enable user interaction with the UE 400. The microphone / speaker 452 may provide voice communication services with the UE 400. The keypad 454 may comprise any suitable buttons for user input to the UE 400. The display 456 may comprise any suitable display, such as, for example, a backlit liquid crystal display (LCD), and may further include a touchscreen display for additional user input modes. The user interface 450 may thus be a means for providing instructions (e.g., audible and / or visual instructions) to a user and / or for receiving user input (e.g., via user actuation of a sensing device, such as a keypad, touchscreen, microphone, etc.).

[0084]

[0095] In one aspect, the UE 400 may include a sidelink manager 470 coupled to the processing system 410. The sidelink manager 470 may be a hardware, software, or firmware component that, when executed, causes the UE 400 to perform the operations described herein. For example, the sidelink manager 470 may be a software module stored in the memory 414 and executable by the processing system 410. As another example, the sidelink manager 470 may be a hardware circuit (e.g., an ASIC, a field programmable gate array (FPGA), etc.) within the UE 400.

[0085]

[0096] Communications over the sidelink may use frame structures and numerology similar to those used in LTE and NR. Figure 5 is a diagram 500 illustrating example frame structures for use on the sidelink according to aspects of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0086]

[0097] In LTE and NR, the system bandwidth is partitioned into multiple (K) orthogonal subcarriers, also commonly referred to as tones or bins. Each subcarrier may be modulated with data. Typically, modulation symbols are sent using orthogonal frequency division multiplexing (OFDM) in the frequency domain and single-carrier frequency division multiplexing (SC-FDM) in the time domain. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system bandwidth. For example, the subcarrier spacing may be 15 kHz, and the minimum resource allocation (resource block) may be 12 subcarriers (or 180 kHz). Therefore, the nominal fast Fourier transform (FFT) size may be equal to 128, 256, 512, 1024, or 2048 for bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0087]

[0098] LTE supports a single numerology (subcarrier spacing (SCS), symbol length, etc.). In contrast, NR may support multiple numerologies (μ), e.g., subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz (μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or greater may be available. At each subcarrier spacing, there are 14 symbols per slot. For a 15 kHz SCS (μ=0), there is one slot per subframe, 10 slots per frame, a slot duration of 1 millisecond (ms), a symbol duration of 66.7 microseconds (μs), and a maximum nominal system bandwidth (MHz) of 50 with a 4K FFT size. For a 30 kHz SCS (μ = 1), there are two slots per subframe, 20 slots per frame, a slot duration of 0.5 ms, and a symbol duration of 33.3 μs, resulting in a maximum nominal system bandwidth (MHz) of 100 for a 4K FFT size. For a 60 kHz SCS (μ = 2), there are four slots per subframe, 40 slots per frame, a slot duration of 0.25 ms, and a symbol duration of 16.7 μs, resulting in a maximum nominal system bandwidth (MHz) of 200 for a 4K FFT size. For a 120 kHz SCS (μ = 3), there are eight slots per subframe, 80 slots per frame, a slot duration of 0.125 ms, and a symbol duration of 8.33 μs, resulting in a maximum nominal system bandwidth (MHz) of 400 for a 4K FFT size. For a 240 kHz SCS (μ=4), there are 16 slots per subframe and 160 slots per frame, with a slot duration of 0.0625 ms, a symbol duration of 4.17 μs, and a maximum nominal system bandwidth (MHz) of 800 with a 4K FFT size.

[0088]

[0099] In the example of Figure 5, a 15 kHz numerology is used. Thus, in the time domain, a 10 ms frame is divided into 10 equally sized subframes of 1 ms each, with each subframe containing one time slot. In Figure 5, time is represented horizontally (on the X-axis) and increases from left to right, and frequency is represented vertically (on the Y-axis) and increases (or decreases) from bottom to top.

[0089]

[0100] A resource grid may be used to represent a time slot, with each time slot including one or more time-aligned resource blocks (RBs) (also called physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In the numerology of FIG. 5, for a standard cyclic prefix, an RB may include 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB may include 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0090]

[0101] Various sidelink physical channels can be transmitted on resource elements of a slot of a radio frame. A sidelink physical channel corresponds to a set of resource elements carrying information originating from higher layers. For the NR sidelink, the following sidelink physical channels are defined: Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Feedback Channel (PSFCH). These channels are described in 3GPP Technical Specification (TS) 38.211, which is publicly available and incorporated herein by reference in its entirety.

[0091]

[0102] As shown in Figure 5, some of the resource elements carry physical RF signals. Sidelink physical signals correspond to sets of resource elements used by the physical layer and do not carry information originating from higher layers. For the NR sidelink, the following sidelink physical signals are defined: Demodulation Reference Signal (DMRS), Channel State Information Reference Signal (CSI-RS), Phase Tracking Reference Signal (PT-RS), Sidelink Primary Synchronization Signal (S-PSS), and Sidelink Secondary Synchronization Signal (S-SSS). Exemplary locations of these signals are labeled "R" in Figure 5. These signals are described in 3GPP TS38.211. In addition, the UE may also transmit Positioning Reference Signals (PRS), Tracking Reference Signals (TRS), etc. for positioning purposes.

[0092]

[0103] A collection of resource elements (REs) used to transmit a PRS is called a "PRS resource." The collection of resource elements may span multiple PRBs in the frequency domain and "N" (e.g., one or more) consecutive symbols within a slot in the time domain. Within a given OFDM symbol in the time domain, the PRS resource occupies consecutive PRBs in the frequency domain.

[0093]

[0104] It should be noted that the terms "positioning reference signal" and "PRS" generally refer to specific reference signals used for positioning in NR and LTE systems. However, as used herein, the terms "positioning reference signal" and "PRS" refer to any type of reference signal that can be used for positioning, including, but not limited to, PRS defined in LTE and NR, tracking reference signal (TRS), phase tracking reference signal (PT-RS), cell-specific reference signal (CRS), channel state information reference signal (CSI-RS), demodulation reference signal (DMRS), primary synchronization signal (PSS), secondary synchronization signal (SSS), synchronization signal block (SSB), sounding reference signal (SRS), uplink positioning reference signal (UL-PRS), etc. In addition, the terms "positioning reference signal" and "PRS" may refer to downlink, uplink, or sidelink positioning reference signals, unless the context indicates otherwise. If further distinction between PRS types is required, a downlink positioning reference signal may be referred to as a "DL-PRS," an uplink positioning reference signal (e.g., SRS-for-positioning, PT-RS) may be referred to as a "UL-PRS," and a sidelink positioning reference signal may be referred to as a "SL-PRS." Additionally, for signals that may be transmitted in the uplink, downlink, and sidelink directions (e.g., DMRS, PT-RS, etc.), the signals may be prepended with "UL," "DL," or "SL," respectively, to distinguish the direction. For example, a "UL-DMRS" may be differentiated from a "SL-DMRS."

[0094]

[0105] Link-level ranging signals can be used to estimate distances between pairs of V-UEs or between a V-UE and a roadside unit (RSU). FIG. 6 illustrates an example wireless communication system 600 in which a V-UE 604 is exchanging ranging signals with an RSU 610 and another V-UE 606 according to aspects of the present disclosure. As shown in FIG. 6, wideband (e.g., FR1) ranging signals (e.g., Zadoff-Chu sequences) are transmitted by both endpoints (e.g., the V-UE 604 and the RSU 610, and the V-UE 604 and the V-UE 606). In one aspect, the ranging signals may be positioning reference signals (e.g., SL-PRS). Upon receiving the ranging signals from the transmitter (e.g., the V-UE 604), the receiver (e.g., the RSU 610 and / or the V-UE 606) estimates the time of arrival (ToA) of the first multipath of the ranging signals using channel estimation. The receiver then responds by sending a ranging signal including the calculated ToA to the transmitter. The transmitter calculates the ToA of the response signal and uses both estimated ToAs to estimate the distance between the transmitter and receiver. Note that this positioning procedure assumes that the V-UEs involved are time-synchronized (i.e., their system frame time is the same as or a known offset relative to the other V-UE(s)). Furthermore, while FIG. 6 shows two V-UEs, it will be appreciated that they need not be V-UEs but instead could be any other type of UE capable of sidelink communication.

[0095]

[0106] As can be seen, the ranging accuracy improves with the bandwidth of the ranging signal. In particular, a higher bandwidth can better separate different multipaths of the ranging signal.

[0096]

[0107] A three-phase protocol may be used for transmitting ranging signals (e.g., SL-PRS) used for positioning. FIG. 7 is a timeline 700 illustrating the three-phase protocol according to an aspect of the present disclosure. As shown in FIG. 7, the three-phase protocol occurs periodically, such as every second. In a first phase 710, the transmitter (e.g., V-UE 604, RSU 610) broadcasts the relative location of its antenna(s) (compared to the transmitter's central location), the identifiers (IDs) of the sequences to be transmitted by the antenna(s) in the second phase 720, and the time / frequency resources on which the sequences are transmitted in the second phase 720.

[0097]

[0108] In the second phase 720, the transmitter transmits a wideband sequence (e.g., SL-PRS) with the determined sequence ID and on the determined time / frequency resource. In the third phase 730, the transmitter broadcasts its GPS location, pseudoranges to one or more satellites, and / or the orientation it had during the second phase. It also broadcasts the ToAs from the second phase 720. That is, it broadcasts the ToAs of any SL-PRS received during the second phase 720. Note that in V2I positioning, only the RSU needs to perform the third phase 730.

[0098]

[0109] In one aspect, all V-UEs and RSUs may be configured (e.g., by applicable standards) to follow this three-phase protocol. Thus, during each phase, the transmitter may also receive signals from other V-UEs / RSUs containing the same type of information as the transmitter transmitted. In that way, both the transmitter and the receiver can estimate the distance between themselves and other V-UEs / RSUs.

[0099]

[0110] FIG. 8 illustrates two resource allocation modes for transmission on the NR sidelink according to aspects of the present disclosure. In a first mode 810 (labeled “Mode 1”), the base station 802 (e.g., a gNB) allocates time / frequency resources for sidelink communication between participating V-UEs. Thus, in the example of FIG. 8, the base station 802 allocates time / frequency resources for the sidelink between V-UE 804 and V-UE 806. The transmitter (e.g., V-UE 804) uses the allocated resources to transmit ranging signals (e.g., SL-PRS) according to the three-phase protocol described above with reference to FIG. 7. That is, the transmitter transmits first, second, and third phase signals on the resources allocated by the base station 802. In a second mode 820 (labeled “Mode 2”), the participating UEs 804 and 806 autonomously select the sidelink resources to use for transmission of the three-phase ranging signals. A V-UE can only use the first mode if it has cellular coverage, and can use the second mode whether it has cellular coverage or not. Note that while Figure 8 shows two V-UEs, it will be appreciated that they do not have to be V-UEs, but instead can be any other type of UE capable of sidelink communication.

[0100]

[0111] Signaling over the sidelink is the same between the two resource allocation modes. From the receiver's (e.g., V-UE 806) perspective, there is no difference between the modes. That is, it does not matter to the receiver whether the resources for the ranging signal are allocated by the base station 802 or the transmitter UE.

[0101]

[0112] Additionally, as described above with reference to Figure 3, the NR sidelink supports HARQ retransmissions. In a first mode, a base station (e.g., base station 802) provides dynamic grants for HARQ feedback or activates configured sidelink grants. The sidelink feedback can be reported back to the base station by the transmitting UE (e.g., V-UE 804).

[0102]

[0113] Each established sidelink includes a PSCCH carrying sidelink control information (SCI). The first-phase control (referred to as "SCI-1") is transmitted on the PSCCH and contains information for resource allocation and for decoding the second-phase control (referred to as "SCI-2"). The second-phase control is transmitted on the PSCCH and contains information for decoding data to be transmitted on the sidelink shared channel (SCH). While the first-phase control information is decodable by all UEs, the second-phase control information may contain a format that is decodable only by some UEs. This ensures that new features can be introduced in the second-phase control while maintaining backward compatibility of resource reservations in the first-phase control.

[0103]

[0114] Both first-stage control and second-stage control use a physical downlink control channel (PDCCH) polar coding chain, as shown in FIG. 9. FIG. 9 is a diagram 900 illustrating how an SCH is established on a sidelink between two or more UEs according to an aspect of the present disclosure. In particular, information in SCI-1 902 is used for resource allocation 904 (by the network or the involved UEs) for SCI-2 906 and SCH 908. Furthermore, information in SCI-1 902 is used to determine / decode the content of SCI-2 906 transmitted on the allocated resources. Thus, a receiving UE needs both resource allocation 904 and SCI-1 902 to decode SCI-2 906. Information in SCI-2 906 is then used to determine / decode SCH 908.

[0104]

[0115] A UE may use round-trip time (RTT) positioning techniques with multiple other UEs or RSUs to determine its location based on ranging signals to / from the other participating UEs / RSUs and their known locations. FIG. 10 is a diagram 1000 illustrating example timing of RTT signals between a target UE 1004 (labeled “UE2”) and two assisting UEs, namely, 1002 (labeled “UE1”) and 1006 (labeled “UE3”), according to an aspect of the present disclosure. The UEs 1002-1006 may correspond to any of the UEs described herein and, in particular, may be V-UEs. In FIG. 10, the target UE 1004 is attempting to estimate its location, and the assisting UEs 1002 and 1006 have known locations (e.g., from GPS).

[0105]

[0116] In the example of FIG. 10, the target UE 1004 receives a ranging signal (e.g., SL-PRS) from the assisting UE 1002 and responds with its own ranging signal (e.g., SL-PRS). The ranging signal may be transmitted on time / frequency resources allocated by the network (e.g., a base station or location server) or one of the involved UEs, as described above with reference to FIG. 8. This allows the receiver UE(s) to know on which frequency and at what time to measure the ranging signal. In the example of FIG. 10, the received ranging signal is T prop,UE1-UE2 The length of time between the receiving of the ranging signal from the assisting UE 1002 and the transmission of the reply ranging signal by the target UE 1004 is called "T UE2,Rx-Tx " or "UE2 Rx-Tx", where "Rx-Tx" stands for "receive-transmit". The response ranging signal is UE2,Rx-Tx and a measurement report containing the value of (T prop,UE1-UE2 (assumed to be equal to)T prop,UE2-UE1 , which has a certain propagation time between the target UE 1004 and the supporting UE 1002, called .

[0106]

[0117] The response ranging signal from the target UE 1004 also prop,UE2-UE3 10) as the response ranging signal to the assisting UE 1002. Alternatively, this may be a different ranging signal transmitted by the target UE 1004 at approximately the same time (in the example of FIG. 10) as the response ranging signal to the assisting UE 1002. UE3,Rx-Tx After some delay in the second assisting UE 1006, referred to as “UE3 Rx-Tx”, the second assisting UE 1006 transmits a response ranging signal to the target UE 1004. The response ranging signal is UE3,Rx-Tx and a measurement report containing the value of (T prop,UE2-UE3 (assumed to be equal to)T prop,UE3-UE2 , and has a certain propagation time between the assisting UE 1006 and the target UE 1004, called the propagation time .

[0107]

[0118] The transmission and reception times of the ranging signal and T UE2,Rx-Tx and T UE3,Rx-Tx Based on the value of , the positioning entity (e.g., target UE 1004) determines the time of flight (i.e., T in the example of FIG. 10) between the target UE 1004 and the assisting UEs 1002 and 1006. prop,UE1-UE2 and / or T prop,UE2-UE1 and T prop,UE2-UE3 and / or T prop,UE3-UE2) can be calculated. Based on the time of flight and the speed of light, the positioning entity can calculate the distance between the target UE 1004 and the assisting UEs 1002 and 1006. Based on these distances, the positioning entity can estimate the relative location of the target UE 1004 with respect to the assisting UEs 1002 and 1006. If the assisting UEs 1002 and 1006 have known locations (e.g., GPS coordinates received from the assisting UEs 1002 and 1006), the positioning entity can estimate the absolute location of the target UE 1004 based on the distance between the target UE 1004 and the assisting UEs 1002 and 1006 and the known locations of the assisting UEs 1002 and 1006. If the assisting UEs 1002 and 1006 provide their locations, they may also provide an uncertainty or precision level associated with the locations.

[0108]

[0119] 11 is a diagram 1100 illustrating example timing of RTT signals exchanged between a target UE 1104 (labeled “UE2”) and two assisting UEs 1102 (labeled “UE1”) and 1106 (labeled “UE3”), according to an aspect of the present disclosure. The UEs 1102-1106 may correspond to any of the UEs described herein and, in particular, may be V-UEs. In FIG. 11, the target UE 1104 is attempting to estimate its location, and the assisting UEs 1102 and 1106 have known locations (e.g., from GPS).

[0109]

[0120] In the example of FIG. 11, the first supporting UE 1102 receives the first signal at a certain propagation time T prop,UE1-UE2 The ranging signal also transmits a ranging signal (e.g., SL-PRS) that is received at the target UE 1104 after a certain propagation time T prop,UE1-UE3 11, this is a known propagation time or can be derived since the locations of the assisting UEs 1102 and 1106 are known.

[0110]

[0121] T UE2,Rx-Tx After some UE processing time at the target UE 1104, referred to as prop,UE2-UE1 The second supporting UE 1106 also receives / measures the first supporting UE 1102 after a certain propagation delay T prop,UE2-UE3 As explained above, the response ranging signal is received / measured after the UE processing time T UE2,Rx-Tx The measurement report may include:

[0111]

[0122] The second supporting UE 1106 is UE-Rx-UE-Rx Or more simply, T Rx-Rx The second assisting UE 1106 determines the time difference, referred to as T, between the ToA of the ranging signal transmitted by the first assisting UE 1102 and the ToA of the reply ranging signal transmitted by the target UE 1104. UE-Rx-UE-Rx The measurement report is sent to a positioning entity (eg, target UE 1104) that reports the measurements.

[0112]

[0123] The distance between the second assisting UE 1106 and the target UE 1104 may then be calculated based on the following observations:

[0113]

number

[0114]

[0124] Based on these distances, the positioning entity can estimate the relative location of the target UE 1104 with respect to the assisting UEs 1102 and 1106. If the assisting UEs 1102 and 1106 have known locations (e.g., GPS coordinates received from the assisting UEs 1102 and 1106), the positioning entity can estimate the absolute location of the target UE 1104 based on the distance between the target UE 1104 and the assisting UEs 1102 and 1106 and the known locations of the assisting UEs 1102 and 1106. If the assisting UEs 1102 and 1106 provide their locations, they may also provide an uncertainty or accuracy level associated with the locations.

[0115]

[0125] It should be noted that although Figures 10 and 11 show the RTT timing between the target UE and two assisting UEs, it will be appreciated that there may be more or less than three assisting UEs.

[0116]

[0126] This disclosure provides techniques for sidelink-assisted positioning. In a first scenario for sidelink-assisted positioning, the assisting UEs (e.g., assisting UEs 1102 and 1106) may have cellular coverage (i.e., cellular connectivity to a base station), and the target UE (e.g., target UE 1104) may not have coverage (i.e., cellular connectivity to a base station). Alternatively, the target UE may have coverage, but it may be very poor, and thus the UE still cannot receive transmissions from the base station.

[0117]

[0127] In this scenario, the target UE can initiate a location request by sending a request to each of any nearby (assisting) UEs via a sidelink established with those UEs. The sidelink may be established at the time of the location request or may have been established previously for other reasons. The assisting UE(s) receive the location requests and forward them to the network (e.g., a serving base station or a location server). In response, the network allocates time / frequency resources (e.g., resource allocation 904) to each of the assisting UEs via the Uu interface for the ranging signal (e.g., SL-PRS) to be used for the respective positioning procedure. However, the target UE does not receive this Uu link and resource allocation information. Instead, the assisting UE sends a sidelink transmission to the target UE that includes a ranging signal configuration in a selected subchannel. In particular, the assisting UE transmits SCI-2 that includes the ranging signal configuration received from the network. However, the assisting UE first transmits SCI-1, which enables the target UE to decode the subsequent SCI-2, as described above with reference to FIG. 9. Once the target UE has an allocated ranging signal configuration to use for the positioning procedure with each assisting UE, it can transmit and receive ranging signals on those resources as described above with reference to Figures 10 and 11.

[0118]

[0128] In a second scenario for sidelink-assisted positioning, neither the target UE nor the assisting UE may have cellular coverage. In this case, the target UE transmits a location request to the assisting UE via the sidelink established with each assisting UE, and the assisting UE can select ranging signal (e.g., SL-PRS) time / frequency resources without network coordination. The assisting UE then sends a sidelink transmission to the target UE including the selected ranging signal configuration in the selected subchannel. In particular, unlike the first option, the assisting UE transmits SCI-2 including the selected ranging signal configuration without network involvement. Furthermore, the assisting UE first transmits SCI-1, which enables the target UE to decode the subsequent SCI-2, as described above with reference to FIG. 9. Once the target UE has an allocated ranging signal configuration to use for the positioning procedure with each assisting UE, it can transmit and receive ranging signals on those resources as described above with reference to FIG. 10 and FIG. 11.

[0119]

[0129] Referring more particularly to the second scenario, when a non-coverage assisting UE responds to a location request from a target UE, the assisting UE must select a time / frequency resource (e.g., RE) on which to transmit SL-PRS back to the target UE. Because multiple UEs assisting a positioning session with the target UE may not have coverage, the SL-PRS resource selected by one assisting UE may conflict with the SL-PRS resource selected by another assisting UE.

[0120]

[0130] Thus, this disclosure provides techniques for avoiding “PRS collisions.” In one aspect, the assisting UE chooses an SL-PRS resource based on a deterministic function of various parameters (described below) derived relative to either the time / frequency resource carrying the SCI-1 / SCI-2 containing the assisting UE's response to the location request and the time / frequency resource of the PSCCH and / or PSSCH that contained the location request.

[0121]

[0131] In the time domain, time resources (e.g., symbols, slots, subframes, repetitions, etc.) allocated to SL-PRS transmissions may be derived based on a common / deterministic function. As a first option, the time domain resources for SL-PRS transmissions may be derived based on a deterministic function of a subchannel of a PSCCH or PSSCH associated with the location request. One PSCCH may schedule multiple PSSCHs. Thus, in one aspect, if a PSCCH is associated with multiple PSSCHs, the supporting UE may select, for example, the index of the PSSCH with the smallest or largest index value to derive the time domain resources for the SL-PRS.

[0122]

[0132] As a second option, the time-domain resources for SL-PRS transmissions may be derived based on a deterministic function of the source ID of the target UE that sent the location request. This option would be beneficial in the following example scenario. Specifically, a responding UE may need to transmit SL-PRS resources tailored to a specific target UE. For example, the transmit beam and / or path loss may be specific to the target UE, and therefore, different SL-PRS resources would need to be transmitted to different target UEs. However, if two different UEs happen to send location requests in the same slot / subchannel and the source ID is not part of the decision procedure for determining the time-domain resources for SL-PRS, the responding UE would not be able to transmit two SL-PRS resources tailored to different UEs. Instead, the responding UE would select SL-PRS resources for both target UEs based on the slot / subchannel associated with the location request (first option). However, because the slot / subchannel is the same for both UEs in this scenario, the selected PRS resources would be the same for both target UEs. Therefore, it would be beneficial for the PRS resources to be derived based on both the slot / subchannel and the source ID.

[0123]

[0133] As a third option, the time domain resources for PRS transmissions can be derived based on a deterministic function of the destination ID of the PSCCH associated with the location request. This destination ID can indicate whether the location request is unicast (i.e., targeted to a specific assisting UE), groupcast (i.e., targeted to a specific group of UEs), or broadcast (i.e., targeted to any listening UEs). Making the time domain resources for SL-PRS a function of the destination ID would allow a responding UE to send multiple SL-PRS (even to the same target UE participating in multiple groups). This factor can therefore make SL-PRS transmissions group-specific.

[0124]

[0134] As a fourth option, the time domain resources for SL-PRS transmissions may be derived based on a deterministic function of pseudo-random variables and / or scrambling seeds. In this case, configured scrambling seeds configured in both the target and supporting UEs from a higher layer (e.g., Layer 2, Layer 3, or application layer) may be used. This may provide additional randomization of the time domain resources used for SL-PRS transmissions.

[0125]

[0135] As a fifth option, the time domain resources for SL-PRS transmissions can be derived based on a deterministic function of the above combination. In this case, which of the aforementioned factors is used and the deterministic function can be configured by a higher layer (e.g., Layer 2, Layer 3, or application layer). Alternatively, this can be related to the band or frequency range (e.g., FR1 or FR2). For example, in the case of FR2, the source ID (second option) is important because it allows the responding UE to correctly form its transmit beam to the target UE.

[0126]

[0136] There are several options for selecting frequency resources for SL-PRS transmission. First, SCI-2 may include an additional frequency-domain allocation field (e.g., subband ID, start / end PRB, etc.) dedicated to signaling frequency-domain resources for SL-PRS. Second, the frequency-domain allocation field of SCI-2 (normally used to schedule PSSCH) may instead be used to schedule only SL-PRS. In this case, PSSCH cannot be scheduled. Third, an additional frequency-domain allocation field may be added in SCI-2 that provides PRS allocation in a differential / relative manner with respect to the frequency-domain allocation field of PSSCH. For example, if PSSCH is in a set of subbands, SL-PRS may be transmitted in the same subband as PSSCH plus another subband below and / or above, as shown in Figure 12.

[0127]

[0137] 12 is a diagram 1200 illustrating the relative time and frequency relationship between an example PSSCH resource 1220 and an example PRS resource 1210, in accordance with an aspect of the present disclosure. The PRS resource 1210 may be an SL-PRS resource. As can be seen, the PRS resource 1210 is transmitted in the same subband as the PSSCH resource 1220 plus at least one subband below and above the PSSCH resource 1220.

[0128]

[0138] 13 illustrates an example method 1300 for wireless communication according to an aspect of the present disclosure. In one aspect, the method 1300 may be performed by a supporting UE (e.g., any of the UEs described herein). As a specific example, the supporting UE may correspond to the UE 1102, the UE 1106, the UE 1202, or the UE 1206.

[0129]

[0139] At 1310, the assisting UE receives a request to perform a positioning procedure (e.g., RTT) from the target UE (e.g., any of the UEs described herein) via a sidelink between the assisting UE and the target UE. As a specific example, the target UE may correspond to the UE 1104 or the UE 1204. In one aspect, both the assisting UE and the target UE are out of network coverage (i.e., have no cellular / network coverage, e.g., as in mode 2 of FIG. 8). In one aspect, operation 1310 may be performed by the transceiver 404, the processing system 410, the memory 414, and / or the sidelink manager 470, any or all of which may be considered means for performing this operation.

[0130]

[0140] At 1320, the assisting UE determines, based at least on the request, a set of time and / or frequency resources upon which to transmit one or more positioning reference signals for the positioning procedure. In an aspect, operation 1320 may be performed by the transceiver 404, the processing system 410, the memory 414, and / or the sidelink manager 470, any or all of which may be considered means for performing this operation.

[0131]

[0141] At 1330, the assisting UE transmits one or more positioning reference signals to the target UE over the set of time and / or frequency resources. In an aspect, operation 1330 may be performed by the transceiver 404, the processing system 410, the memory 414, and / or the sidelink manager 470, any or all of which may be considered a means for performing this operation.

[0132]

[0142] 14 illustrates an example method 1400 for wireless communication according to an aspect of the present disclosure. In one aspect, the method 1400 may be performed by a target UE (e.g., any of the UEs described herein). As a specific example, the target UE may correspond to the UE 1104 or the UE 1204.

[0133]

[0143] At 1410, the target UE transmits a request to perform a positioning procedure (e.g., RTT) to at least one assisting UE (e.g., any of the UEs described herein) via a sidelink between the at least one assisting UE and the target UE. As a specific example, the at least one assisting UE may correspond to UE 1102, UE 1106, UE 1202, or UE 1206. In one aspect, both the target UE and the at least one assisting UE are out of network coverage (i.e., have no cellular / network coverage, e.g., as in mode 2 of FIG. 8). In one aspect, operation 1410 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, any or all of which may be considered means for performing this operation.

[0134]

[0144] At 1420, the target UE determines, based at least on the request, a set of time and / or frequency resources upon which to transmit one or more positioning reference signals from the at least one assisting UE for the positioning procedure. In an aspect, operation 1420 may be performed by the transceiver 404, the processing system 410, the memory 414, and / or the sidelink manager 470, any or all of which may be considered means for performing this operation.

[0135]

[0145] At 1430, the target UE transmits one or more positioning reference signals to the at least one assisting UE over the set of time and / or frequency resources. In an aspect, operation 1430 may be performed by the transceiver 404, the processing system 410, the memory 414, and / or the sidelink manager 470, any or all of which may be considered a means for performing this operation.

[0136]

[0146] As will be appreciated, a technical advantage of methods 1300 and 1400 is the coordination of positioning reference signals transmitted over the sidelink, reducing or even eliminating collisions between such positioning reference signals.

[0137]

[0147] In the above detailed description, it can be seen that different features are grouped together in examples. This mode of disclosure should not be understood as an intention that the exemplary clauses have more features than are expressly set forth in each clause. Rather, various embodiments of the present disclosure may include fewer than all features of each disclosed exemplary clause. Accordingly, the following clauses should be considered incorporated herein, with each clause standing as a separate example by itself. While each dependent clause may refer to a specific combination with one of the other clauses in the clause, the aspect(s) of that dependent clause are not limited to that specific combination. It will be appreciated that other exemplary clauses may also include combinations of the dependent clause(s) aspect(s) with the subject matter of any other dependent clause or independent clause, or any combination of features with other dependent and independent clauses. The various embodiments disclosed herein expressly include combinations of specific combinations (e.g., inconsistent aspects, such as defining an element as both an insulator and a conductor) unless these combinations are expressly expressed or can be readily inferred to be unintended. Furthermore, it is also contemplated that aspects of a clause may be included in any other independent clause, even if that clause is not directly dependent on that independent clause.

[0138]

[0148] Example implementations are described in the following numbered clauses.

[0139]

[0149] Clause 1. A method for wireless communications, implemented in an assisting user equipment (UE), comprising: receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE; determining a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; transmitting an indication of the set of time and / or frequency resources to the target UE via the sidelink; and transmitting the one or more positioning reference signals to the target UE on the set of time and / or frequency resources.

[0140]

[0150] Clause 2. The method of clause 1, wherein the assisting UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

[0141]

[0151] Clause 3. The method of clause 2, wherein the one or more parameters are derived relative to the time and / or frequency resources at which the indication of the set of time and / or frequency resources is transmitted to the target UE.

[0142]

[0152] Clause 4. The method of clause 3, wherein an indication of the set of time and / or frequency resources is transmitted to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

[0143]

[0153] Clause 5. The method of clause 2, wherein the one or more parameters are derived relative to a time and / or frequency resource when the request to perform the positioning procedure is received.

[0144]

[0154] Clause 6. The method according to clause 5, wherein the request to perform the positioning procedure is received via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink.

[0145]

[0155] Clause 7. The method of any of clauses 2 to 6, wherein one or more parameters are used to determine time domain resources of the set of time and / or frequency resources.

[0146]

[0156] Clause 8. The method of clause 7, wherein one of the one or more parameters comprises a subchannel of the PSCCH or PSSCH upon which a request to perform a positioning procedure is received.

[0147]

[0157] Clause 9. The method of any of clauses 7 to 8, wherein one of the one or more parameters comprises a source identifier of the target UE.

[0148]

[0158] Clause 10. The method according to any one of clauses 7 to 9, wherein one of the one or more parameters comprises a destination identifier of the PSCCH when a request to perform a positioning procedure is received.

[0149]

[0159] Clause 11. The method of clause 10, wherein the destination identifier relates to a unicast, groupcast, or broadcast.

[0150]

[0160] Clause 12. The method of any of clauses 7 to 11, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed.

[0151]

[0161] Clause 13. The method of clause 12, wherein the pseudo-random variable or scrambling seed is configured by higher layers of the supporting UE.

[0152]

[0162] Clause 14. The method of any of clauses 7 to 13, wherein the selection of one of the one or more parameters is configured by higher layers in the supporting UE.

[0153]

[0163] Clause 15. The method of any of clauses 1 to 14, wherein the request to perform a positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources.

[0154]

[0164] Clause 16. The method of clause 15, wherein the request to perform the positioning procedure is received in SCI-2 via a side link.

[0155]

[0165] Clause 17. The method of any of clauses 1 to 16, wherein the frequency domain allocation field in the request to perform a positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for one or more positioning reference signals.

[0156]

[0166] Clause 18. The method of any of clauses 1 to 16, wherein an additional frequency domain allocation field in the request to perform a positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for one or more positioning reference signals.

[0157]

[0167] Clause 19. The method of any of clauses 1 to 18, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure.

[0158]

[0168] Clause 20. An apparatus comprising a memory and at least one processor communicatively coupled to the memory, wherein the memory and the at least one processor are configured to perform the method of any of clauses 1 to 19.

[0159]

[0169] Clause 21. Apparatus comprising means for carrying out the method according to any of clauses 1 to 19.

[0160]

[0170] Clause 22. A non-transitory computer-readable medium having stored thereon computer-executable instructions, the computer-executable comprising at least one instruction for causing a computer or processor to perform a method according to any of clauses 1 to 19.

[0161]

[0171] Additional implementation examples are described in the numbered clauses below.

[0162]

[0172] Clause 1. A method for wireless communications, implemented in an assisting user equipment (UE), comprising: receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; determining, based on at least the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0163]

[0173] Clause 2. The method of clause 1, wherein the assisting UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

[0164]

[0174] Clause 3. The method of clause 2, further comprising transmitting an indication of the set of time and / or frequency resources to the target UE via a sidelink.

[0165]

[0175] Clause 4. The method of clause 3, further comprising deriving one or more parameters relative to the time and / or frequency resources at which the indication of the set of time and / or frequency resources is transmitted to the target UE.

[0166]

[0176] Clause 5. The method of clause 4, further comprising transmitting an indication of the set of time and / or frequency resources to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

[0167]

[0177] Clause 6. The method of any of clauses 2 to 5, further comprising deriving one or more parameters relative to the time and / or frequency resources when the request to perform the positioning procedure is received.

[0168]

[0178] Clause 7. The method of any of clauses 2 to 6, further comprising determining time domain resources of the set of time and / or frequency resources based on one or more parameters.

[0169]

[0179] Clause 8. The method of any of clauses 2 to 7, wherein one of the one or more parameters comprises a PSCCH or a subchannel of a PSSCH upon which a request to perform a positioning procedure is received.

[0170]

[0180] Clause 9. The method of any of clauses 2 to 8, wherein one of the one or more parameters comprises a source identifier of the target UE.

[0171]

[0181] Clause 10. The method according to any one of clauses 2 to 9, wherein one of the one or more parameters comprises a destination identifier of the PSCCH when a request to perform a positioning procedure is received.

[0172]

[0182] Clause 11. The method of clause 10, wherein the destination identifier relates to a unicast, groupcast, or broadcast.

[0173]

[0183] Clause 12. The method of any of clauses 2 to 11, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed.

[0174]

[0184] Clause 13. The method of clause 12, wherein the pseudo-random variable or scrambling seed is configured by higher layers of the supporting UE.

[0175]

[0185] Clause 14. The method of any of clauses 2 to 13, wherein the selection of one of the one or more parameters is configured by higher layers in the supporting UE.

[0176]

[0186] Clause 15. The method of any of clauses 1 to 14, wherein the request to perform a positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources.

[0177]

[0187] Clause 16. The method of clause 15, wherein the request to perform the positioning procedure is received in SCI-2 via a side link.

[0178]

[0188] Clause 17. The method of any of clauses 1 to 16, wherein a frequency domain allocation field of a sidelink control information (SCI) channel associated with a request to perform a positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for one or more positioning reference signals.

[0179]

[0189] Clause 18. A method according to any of clauses 1 to 17, wherein a first set of frequency domain allocation fields of the SCI channel associated with a request to perform a positioning procedure is used to schedule data, and a second set of frequency domain allocation fields of the SCI channel associated with a request to perform a positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for one or more positioning reference signals.

[0180]

[0190] Clause 19. The method of clause 18, wherein the second set of frequency domain allocation fields provides scheduling for one or more positioning reference signals in a differential manner relative to the scheduling of data by the first set of frequency domain allocation fields.

[0181]

[0191] Clause 20. The method according to any one of clauses 1 to 19, wherein the request to perform the positioning procedure is received via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink.

[0182]

[0192] Clause 21. The method of any of clauses 1 to 20, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure.

[0183]

[0193] Clause 22. A method for wireless communication, implemented in a target user equipment (UE), comprising: transmitting a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and transmitting the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0184]

[0194] Clause 23. The method of clause 22, wherein the target UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

[0185]

[0195] Clause 24. The method of clause 23, further comprising transmitting an indication of the set of time and / or frequency resources to at least one assisting UE via a sidelink.

[0186]

[0196] Clause 25. The method of clause 24, further comprising deriving one or more parameters relative to the time and / or frequency resources when the indication of the set of time and / or frequency resources is transmitted to the at least one assisting UE.

[0187]

[0197] Clause 26. The method of clause 25, further comprising sending an indication of the set of time and / or frequency resources to at least one assisting UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

[0188]

[0198] Clause 27. The method of any of clauses 23 to 26, further comprising deriving one or more parameters relative to the time and / or frequency resources when the request to perform the positioning procedure is transmitted.

[0189]

[0199] Clause 28. The method of any of clauses 23 to 27, further comprising determining time domain resources of the set of time and / or frequency resources based on one or more parameters.

[0190]

[0200] Clause 29. The method according to any one of clauses 23 to 28, wherein one of the one or more parameters comprises a subchannel of the PSCCH or PSSCH over which the request to perform the positioning procedure is transmitted.

[0191]

[0201] Clause 30. The method of any of clauses 23 to 29, wherein one of the one or more parameters comprises a source identifier of the target UE.

[0192]

[0202] Clause 31. The method according to any of clauses 23 to 30, wherein one of the one or more parameters comprises a destination identifier of the PSCCH when the request to perform the positioning procedure is sent.

[0193]

[0203] Clause 32. The method of clause 31, wherein the destination identifier relates to a unicast, groupcast, or broadcast.

[0194]

[0204] Clause 33. The method of any of clauses 23 to 32, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed.

[0195]

[0205] Clause 34. The method of clause 33, wherein the pseudo-random variable or scrambling seed is configured by higher layers of the target UE.

[0196]

[0206] Clause 35. The method of any of clauses 23 to 34, wherein the selection of one of the one or more parameters is configured by higher layers of the target UE.

[0197]

[0207] Clause 36. The method of any of clauses 22 to 35, wherein the request to perform a positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources.

[0198]

[0208] Clause 37. The method according to clause 36, wherein the request to perform the positioning procedure is transmitted via a side link in SCI-2.

[0199]

[0209] Clause 38. The method of any of clauses 22 to 37, wherein a frequency domain allocation field of a sidelink control information (SCI) channel associated with a request to perform a positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for one or more positioning reference signals.

[0200]

[0210] Clause 39. The method of any of clauses 22 to 38, wherein a first set of frequency domain allocation fields of the SCI channel associated with the request to perform a positioning procedure is used to schedule data, and a second set of frequency domain allocation fields of the SCI channel associated with the request to perform a positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for one or more positioning reference signals.

[0201]

[0211] Clause 40. The method of clause 39, wherein the second set of frequency domain allocation fields provides scheduling for one or more positioning reference signals in a differential manner relative to the scheduling of data by the first set of frequency domain allocation fields.

[0202]

[0212] Clause 41. The method of any of clauses 22 to 40, further comprising transmitting a request to perform a positioning procedure via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink.

[0203]

[0213] Clause 42. The method of any of clauses 22 to 41, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure.

[0204]

[0214] Clause 43. An apparatus comprising a memory and at least one processor communicatively coupled to the memory, wherein the memory and the at least one processor are configured to perform the method of any of clauses 1 to 42.

[0205]

[0215] Clause 44. Apparatus comprising means for carrying out the method according to any of clauses 1 to 42.

[0206]

[0216] Clause 45. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable comprising at least one instruction for causing a computer or processor to perform a method according to any of clauses 1 to 42.

[0207]

[0217] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0208]

[0218] Furthermore, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0209]

[0219] The various example logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0210]

[0220] The methods, sequences, and / or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in software modules executed by a processor, or in a combination of the two. The software modules may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). Alternatively, the processor and the storage medium may reside as discrete components in the user terminal.

[0211]

[0221] In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy discs, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0212]

[0222] While the above disclosure sets forth exemplary embodiments of the present disclosure, it should be noted that various changes and modifications can be made herein without departing from the scope of the present disclosure as defined by the appended claims. The functions, steps and / or actions of the method claims in accordance with the embodiments of the present disclosure described herein need not be performed in any particular order. Furthermore, although elements of the present disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. The inventions described in the claims of the present application as originally filed are set forth below. [C1] A method for wireless communications, implemented in an assisting user equipment (UE), comprising: receiving a request to perform a positioning procedure from a target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources. A method comprising: [C2] The method of C1, wherein the supporting UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters. [C3] The method of C2, further comprising transmitting an indication of the set of time and / or frequency resources to the target UE via the sidelink. [C4] The method of C3, further comprising deriving the one or more parameters relative to time and / or frequency resources at which the indication of the set of time and / or frequency resources is transmitted to the target UE. [C5] The method of C4, further comprising transmitting the indication of the set of time and / or frequency resources to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message. [C6] The method of C2, further comprising deriving the one or more parameters relative to a time and / or frequency resource when the request to perform the positioning procedure is received. [C7] The method of C2, further comprising determining a time domain resource of the set of time and / or frequency resources based on the one or more parameters. [C8] The method of C2, wherein one of the one or more parameters comprises a subchannel of a PSCCH or a PSSCH on which the request to perform the positioning procedure is received. [C9] The method of C2, wherein one of the one or more parameters comprises a source identifier of the target UE. [C10] The method of C2, wherein one of the one or more parameters comprises a destination identifier of a PSCCH when the request to perform the positioning procedure is received. [C11] The method of C10, wherein the destination identifier is associated with a unicast, groupcast, or broadcast. [C12] The method of C2, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed. [C13] The method of C12, wherein the pseudo random variable or the scrambling seed is configured by a higher layer of the supporting UE. [C14] The method of C2, wherein the selection of one of the one or more parameters is configured by a higher layer of the supporting UE. [C15] The method of C1, wherein the request to perform the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources. [C16] The method of C15, wherein the request to perform the positioning procedure is received via the side link in SCI-2. [C17] The method described in C1, wherein a frequency domain allocation field of a sidelink control information (SCI) channel associated with the request to perform the positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C18] a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule data; The method of claim 1, wherein a second set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C19] The method of C18, wherein the second set of frequency domain allocation fields provides scheduling for the one or more positioning reference signals in a differential manner relative to the scheduling of the data by the first set of frequency domain allocation fields. [C20] The method according to C1, wherein the request to perform the positioning procedure is received via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink. [C21] The method of C1, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure. [C22] A method for wireless communication, implemented in a target user equipment (UE), comprising: sending a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one supporting UE for the positioning procedure; transmitting the one or more positioning reference signals to the at least one supporting UE over the set of time and / or frequency resources; A method comprising: [C23] The method of C22, wherein the target UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters. [C24] The method of C23, further comprising transmitting an indication of the set of time and / or frequency resources to the at least one assisting UE via the sidelink. [C25] The method of C24, further comprising deriving the one or more parameters relative to time and / or frequency resources when the indication of the set of time and / or frequency resources is transmitted to the at least one supporting UE. [C26] The method of C25, further comprising transmitting the indication of the set of time and / or frequency resources to the at least one assisting UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message. [C27] The method of C23, further comprising deriving the one or more parameters relative to a time and / or frequency resource when the request to perform the positioning procedure is transmitted. [C28] The method of C23, further comprising determining a time domain resource of the set of time and / or frequency resources based on the one or more parameters. [C29] The method of C23, wherein one of the one or more parameters comprises a subchannel of a PSCCH or a PSSCH over which the request to perform the positioning procedure is transmitted. [C30] The method of C23, wherein one of the one or more parameters comprises a source identifier of the target UE. [C31] The method of C23, wherein one of the one or more parameters comprises a destination identifier of a PSCCH when the request to perform the positioning procedure is transmitted. [C32] The method of C31, wherein the destination identifier is associated with a unicast, groupcast, or broadcast. [C33] The method of C23, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed. [C34] The method of C33, wherein the pseudo random variable or the scrambling seed is configured by a higher layer of the target UE. [C35] The method of C23, wherein the selection of one of the one or more parameters is configured by a higher layer of the target UE. [C36] The method of C22, wherein the request to perform the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources. [C37] The method described in C36, wherein the request to perform the positioning procedure is transmitted via the side link in SCI-2. [C38] The method described in C22, wherein a frequency domain allocation field of a sidelink control information (SCI) channel associated with the request to perform the positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C39] a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule data; The method of claim 22, wherein a second set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C40] The method of C39, wherein the second set of frequency domain allocation fields provides scheduling for the one or more positioning reference signals in a differential manner relative to the scheduling of the data by the first set of frequency domain allocation fields. [C41] The method of C22, further comprising transmitting the request to perform the positioning procedure via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink. [C42] The method of C22, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure. [C43] Memory and at least one transceiver; at least one processor communicatively coupled to the memory and the at least one transceiver; and a supporting user equipment (UE) comprising: receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; causing the at least one transceiver to transmit the one or more positioning reference signals to the target UE via the set of time and / or frequency resources; A supporting UE configured to cause the [C44] The supporting UE of C43, wherein the at least one processor determines the set of time and / or frequency resources based on a deterministic function of one or more parameters. [C45] The at least one processor 45. The assisting UE of claim 44, further configured to cause the at least one transceiver to transmit an indication of the set of time and / or frequency resources to the target UE via the side link. [C46] The at least one processor The assisting UE of C45, further configured to derive the one or more parameters relative to time and / or frequency resources when the indication of the set of time and / or frequency resources is transmitted to the target UE. [C47] The at least one processor 47. The assisting UE of claim 46, further configured to cause the at least one transceiver to transmit the indication of the set of time and / or frequency resources to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message. [C48] The at least one processor The assisting UE of C44, further configured to derive the one or more parameters relative to a time and / or frequency resource when the request to perform the positioning procedure is received. [C49] The at least one processor The assisting UE of C44, further configured to determine a time domain resource of the set of time and / or frequency resources based on the one or more parameters. [C50] The supporting UE of C44, wherein one of the one or more parameters comprises a PSCCH or a subchannel of a PSSCH on which the request to perform the positioning procedure is received. [C51] The assisting UE of C44, wherein one of the one or more parameters comprises a source identifier of the target UE. [C52] The supporting UE of C44, wherein one of the one or more parameters comprises a destination identifier of a PSCCH when the request to perform the positioning procedure is received. [C53] The supporting UE according to C52, wherein the destination identifier is associated with unicast, groupcast, or broadcast. [C54] The supporting UE of C44, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed. [C55] The supporting UE according to C54, wherein the pseudo random variable or the scrambling seed is configured by a higher layer of the supporting UE. [C56] The supporting UE of C44, wherein the selection of one of the one or more parameters is configured by a higher layer of the supporting UE. [C57] The assisting UE of C43, wherein the request to perform the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources. [C58] The supporting UE according to C57, wherein the request to perform the positioning procedure is received via the side link in SCI-2. [C59] A supporting UE as described in C43, wherein a frequency domain allocation field of a sidelink control information (SCI) channel associated with the request to perform the positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C60] a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule data; A supporting UE as described in C43, wherein a second set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C61] The supporting UE of C60, wherein the second set of frequency domain allocation fields provides scheduling for the one or more positioning reference signals in a differential manner relative to scheduling of the data by the first set of frequency domain allocation fields. [C62] The supporting UE according to C43, wherein the request to perform the positioning procedure is received via a physical sidelink control channel (PSCCH) and / or a physical sidelink shared channel (PSSCH) of the sidelink. [C63] The assisting UE of C43, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure. [C64] Memory and at least one transceiver; at least one processor communicatively coupled to the memory and the at least one transceiver; a target user equipment (UE) comprising: causing at least one transceiver to send a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one supporting UE for the positioning procedure; transmitting, from the at least one transceiver, the one or more positioning reference signals to the at least one supporting UE via the set of time and / or frequency resources; a target UE configured to: [C65] The target UE of C64, wherein the at least one processor determines the set of time and / or frequency resources based on a deterministic function of one or more parameters. [C66] The at least one processor The target UE of C65, further configured to cause the at least one transceiver to transmit an indication of the set of time and / or frequency resources to the at least one assisting UE via the side link. [C67] The at least one processor The target UE of C66, further configured to derive the one or more parameters relative to time and / or frequency resources when the indication of the set of time and / or frequency resources is transmitted to the at least one assisting UE. [C68] The at least one processor The target UE of C67, further configured to cause the at least one transceiver to transmit the indication of the set of time and / or frequency resources to the at least one assisting UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message. [C69] The at least one processor The target UE of C65, further configured to derive the one or more parameters relative to a time and / or frequency resource when the request to perform the positioning procedure is transmitted. [C70] The at least one processor The target UE of C65, further configured to determine a time domain resource of the set of time and / or frequency resources based on the one or more parameters. [C71] The target UE of C65, wherein one of the one or more parameters comprises a subchannel of a PSCCH or a PSSCH over which the request to perform the positioning procedure is transmitted. [C72] The target UE of C65, wherein one of the one or more parameters comprises a source identifier of the target UE. [C73] The target UE of C65, wherein one of the one or more parameters comprises a destination identifier of a PSCCH when the request to perform the positioning procedure is transmitted. [C74] The target UE according to C73, wherein the destination identifier is associated with unicast, groupcast, or broadcast. [C75] The target UE of C65, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed. [C76] The target UE according to C75, wherein the pseudo random variable or the scrambling seed is configured by an upper layer of the target UE. [C77] The target UE of C65, wherein the selection of one of the one or more parameters is configured by an upper layer of the target UE. [C78] The target UE of C64, wherein the request to perform the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources. [C79] The target UE according to C78, wherein the request to perform the positioning procedure is transmitted via the side link in SCI-2. [C80] The target UE described in C64, wherein a frequency domain allocation field of a sidelink control information (SCI) channel associated with the request to perform the positioning procedure is used only to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C81] a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule data; The target UE of C64, wherein a second set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals. [C82] The target UE of C81, wherein the second set of frequency domain allocation fields provides scheduling for the one or more positioning reference signals in a differential manner relative to the scheduling of the data by the first set of frequency domain allocation fields. [C83] The target UE according to C64, wherein the request to perform the positioning procedure is received via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink. [C84] The target UE of C64, wherein the positioning procedure comprises a round trip time (RTT) positioning procedure. [C85] A supporting user equipment (UE), comprising: means for receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; means for determining, based at least on said request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for said positioning procedure; means for transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources; A supporting UE comprising: [C86] A target user equipment (UE), means for transmitting a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; means for determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one assisting UE for the positioning procedure; means for transmitting the one or more positioning reference signals to the at least one supporting UE over the set of time and / or frequency resources; A target UE comprising: [C87] A non-transitory computer-readable medium having stored thereon a set of instructions, the set of instructions comprising one or more instructions that, when executed by one or more processors of a supporting user equipment (UE), receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for the positioning procedure; and transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources. a non-transitory computer-readable medium for causing the supporting UE to perform the following: [C88] A non-transitory computer-readable medium having stored thereon a set of instructions, the set of instructions comprising one or more instructions that, when executed by one or more processors of a target user equipment (UE), sending a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals from the at least one supporting UE for the positioning procedure; transmitting the one or more positioning reference signals to the at least one supporting UE over the set of time and / or frequency resources; a non-transitory computer-readable medium for causing the target UE to perform the following:

Claims

1. 1. A method for wireless communication, implemented in a supporting user equipment (UE), comprising: receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; determining, based at least on said request, a set of time and / or frequency resources for transmitting one or more positioning reference signals for said positioning procedure; and the set of time and / or frequency resources is determined based on a deterministic function of one or more parameters, the one or more parameters being derived with respect to time and / or frequency resources upon which the request to perform the positioning procedure is received or time and / or frequency resources carrying a response to the request; a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule a physical sidelink shared channel (PSSCH); and a second set of frequency-domain allocation fields of the SCI channels associated with the request to perform the positioning procedure is used to schedule frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, the second set of frequency-domain allocation fields of the SCI channels being additional to the first set of frequency-domain fields of the SCI channels. transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources; A method comprising:

2. 1. A method for wireless communication, implemented in a target user equipment (UE), comprising: sending a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals to the at least one assisting UE for the positioning procedure; and the set of time and / or frequency resources is determined based on a deterministic function of one or more parameters, the one or more parameters being derived with respect to time and / or frequency resources on which the request to perform the positioning procedure is transmitted or which carry a response to the request; a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule a physical sidelink shared channel (PSSCH); and a second set of frequency-domain allocation fields of the SCI channels associated with the request to perform the positioning procedure is used to schedule frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, the second set of frequency-domain allocation fields of the SCI channels being additional to the first set of frequency-domain allocation fields of the SCI channels. transmitting the one or more positioning reference signals to the at least one assisting UE over the set of time and / or frequency resources; A method comprising:

3. The method of claim 1 or 2, wherein the assisting UE or target UE, respectively, further determines time domain resources of the set of time and / or frequency resources based on a deterministic function of one or more parameters.

4. deriving said one or more parameters with respect to time and / or frequency resources when an indication of said set of time and / or frequency resources is transmitted to said target UE or at least one assisting UE, respectively; transmitting the indication of the set of time and / or frequency resources via the sidelink in a first Sidelink Control Information (SCI-1) message and / or a second Sidelink Control Information (SCI-2) message to the target UE or at least one assisting UE, respectively; The method of claim 3 further comprising:

5. determining a time domain resource from the set of time and / or frequency resources based on the one or more parameters, wherein one of the one or more parameters is: a sub-channel of the PSCCH or PSSCH on which the request to perform the positioning procedure is received; a source identifier of the target UE, or a destination identifier of the PSCCH when the request to perform the positioning procedure is received; Equipped with The method of claim 3 , wherein the destination identifier is associated with a unicast, groupcast, or broadcast.

6. The method of claim 2 , wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed configured by higher layers of the supporting UE.

7. The method of claim 3 , wherein the selection of one of the one or more parameters is configured by higher layers of the assisting UE or target UE, respectively.

8. The method of claim 1 , wherein the request to perform the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling frequency domain resources of the set of time and / or frequency resources.

9. 9. The method of claim 8, wherein the request to perform the positioning procedure is received via the sidelink in SCI-2.

10. 3. The method of claim 1, wherein the second set of frequency-domain allocation fields provides scheduling for the one or more positioning reference signals in a differential manner relative to scheduling of the PSSCH by the first set of frequency-domain allocation fields.

11. 2. The method of claim 1, wherein the request to perform the positioning procedure is received via a Physical Sidelink Control Channel (PSCCH) and / or a Physical Sidelink Shared Channel (PSSCH) of the sidelink.

12. The method of claim 1 , wherein the positioning procedure comprises a round-trip time (RTT) positioning procedure.

13. A supporting user equipment (UE), means for receiving a request to perform a positioning procedure from the target UE via a sidelink between the assisting UE and the target UE, wherein both the assisting UE and the target UE are out of network coverage; means for determining, based at least on said request, a set of frequency resources and / or a set of time resources for transmitting one or more positioning reference signals for said positioning procedure, wherein: the set of time and / or frequency resources is determined based on a deterministic function of one or more parameters, the one or more parameters being derived with respect to time and / or frequency resources upon which the request to perform the positioning procedure is received or time and / or frequency resources carrying a response to the request; a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule a physical sidelink shared channel (PSSCH); and a second set of frequency-domain allocation fields of the SCI channels associated with the request to perform the positioning procedure is used to schedule frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, the second set of frequency-domain allocation fields of the SCI channels being additional to the first set of frequency-domain fields of the SCI channels. means for transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources; A supporting UE comprising:

14. A target user equipment (UE), means for transmitting a request to perform a positioning procedure to at least one assisting UE via a sidelink between the at least one assisting UE and the target UE, wherein both the target UE and the at least one assisting UE are out of network coverage; means for determining, based at least on the request, a set of time and / or frequency resources for transmitting one or more positioning reference signals to the at least one assisting UE for the positioning procedure, wherein: the set of time and / or frequency resources is determined based on a deterministic function of one or more parameters, the one or more parameters being derived with respect to time and / or frequency resources on which the request to perform the positioning procedure is transmitted or which carry a response to the request; a first set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule a physical sidelink shared channel (PSSCH); and a second set of frequency-domain allocation fields of the SCI channels associated with the request to perform the positioning procedure is used to schedule frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, the second set of frequency-domain allocation fields of the SCI channels being additional to the first set of frequency-domain fields of the SCI channels. means for transmitting the one or more positioning reference signals to the at least one assisting UE over the set of time and / or frequency resources; A target UE comprising:

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